There are two propositions as to how we can change reality: The first proposition which I will call the "metaphysics" proposition, argues that human consciousness can directly influence external reality, this claim is highly controversial though believed to be true by many traditions. A second proposition, denoted as the "psychological" proposition argues that consciousness only affects the experienced reality created by our brain through our senses and not base reality. Most of the following text assumes the "metaphysics" proposition to be true, however, the conclusions are still relevant even if only the "psychological" proposition is true. So whether you believe, we can directly influence or not reality with our conciousness, the last part of this text is still relevant.

Reality

Quantum mechanics is the most successful scientific theory that we have, it has been proven over and over again. However, its results contradict and upend many of our long-held beliefs about reality; it goes against "common sense." One of the most controversial aspects is that it contradicts particles at the most basic level don't seem to exhist as definite objects and instead exist as a probability distribution until measured.This could indicate that there is no inherent reality at the most basic level. What we call reality is a superposition of different possibilities. Reality is a foam of different possible states all coexisting at the same time and then, depending on the interpretation, either: measurements collapse this foam into one distinct possibility or different realities are created in paralel for each one and we just get to experience one of them. Furthermore, the way a measurement is made influences the result. This effect is known as the observer effect. The way your measure a superposition affects the likelihood of the different possibilities. These results have been proven again and again, and while most people think that these effects apply only at small scales, there is nothing stating that they dont apply for larger systems. As above, so below. Therefore, the observer itself can be in a state of superposition to a second observer. And even more interesting, two observers measuring the same phenomenon can be in a superposition with regard to one another until they both compare their results. Meaning that whenever you go outside, you make a measurement of the superposition that is the universe, and you yourself are in a superposition with regards to everyone else. Every observer is processing reality in parallel to each other. Reality is a conjoined effort. Many different authors believe that our reality is some sort of simulation with conciousness as its substrate or source. For example authors like Thomas Campbell and Danny Goler, both believe that reality is a simulation created by conciousness. They both argue, that whenever a superposition is collapsed, the simulation the outcome from a probabily distribution. Therefore, unobserved reality exists as a table with the different possibilities and their probability distribution,this allows the simulation to save resources by only rendering reality when it is observed.

Perception

At every instant your brain via your senses is making measurements and collapsing the superposition. There is some evidence, that the human brain is capable of influencing quantum events. Long running experiments have shown that the human mind can influence random number generators via attention, the effect is slight, but it is there and has been measured. The bottom line is that the brain is capable of influencing reality.
Now that we have established that human brains can change reality via our perception, we have to understand how perception works. Perception occurs subconsciously and will depend on the subconcious beliefs of the observer. The subconcious filters observations that do not allign with its preconceptions. If we take into account the observer effect, the subconcious might also influence the way the superposition to collapse it into an outcome that aligns with your subconcious beliefs. Our concious observer is just a passanger to what our subconcious has already mapped.
It is important to understand that our beliefs shape reality. What we expect to see, changes what we actually see. Nevertheless, reality is the agregated sum of all conciousness running in parelel. Furthermore, reality has rules and is ultimately regulated by energy exchange. So that the believes of others and the rules of reality impact how the waveform collapses. Meaning that while we might be able to slightly tip the scales, if the probability of a particular outcome is extremely low, we might be able improve its likelyhood slight, but it will still remain unlikely to happen.

This explanation of reality is more scientific or pseudo-scientific, however, the same topics can be covered through the lense of religion and magic and ultimately the same conclusions can be reached regardless of the belief system. This same phenomenon that is called the subconscious mind can also be called god or your “higher self” without changing the resulting effects. This means that the explanations offered here are independent of your belief system.

Changing Reality

There are methods to change your beliefs and modify your reality. The rational part of the brain is constantly filtering the information that gets to the unconscious mind. This makes it hard to directly change what the subconcious mind believes. This is why different traditions have created methods to "distract" or "bypass" the rational brain. This include things like: meditation, sigil magic, ritual magic, prayer, alchemy , afirmations, memes, hemi sync. The purpose of all of these methods is to implant beliefs into the subconscious when the rational mind is either exhausted or distracted and most likely to let beliefs pass through unchallenged. By making use of these altered states of mind,you can implant believes that align with what you wish to achieve. Unfortunately, since reality is a common effort, if others do not share your vision for reality, it will be hard for it to manifest. They have think that whatever you are trying to achieve is likely or possible. If you have a extremely strong will, you might be able to override slightly the reality of others. But it is much easier to change the beliefs of enough people, to impose your vision of reality. My playing with how they perceive you for example, you might be able to enact change on yourself. This is best resumed by the common trope of "fake it until you make it".

Program or be programed

Your mind is a battlefield. Many different groups are fighting for your attention and to gain access into your subconcious. By changing your beliefs and that of others, they are able to ground and manifest their vision of reality. This is done by groups like goverments, corporations and religions. Our desires and our beliefs have been feed to us without our choosing. Mass media for example,chooses the narratives to direct our attention and more neferiously to implant beliefs into us. They are not concerned with showing you the truth, they care only with deciding what you focus on. For example, the news creates a feedback loop by influencing the beliefs of its readers and manifesting the reality that they show. Be wary of anything you consume and discard anything that doesn’t serve your porpuse and tries to influence the way you view reality. You have the power to choose what is really important to you and your loved ones, do not let your priorities be given to you by others. Since we create reality, we should all take an active involvement in this process. A lot of us have become lazy and complacent. We let reality be fed to us. Know that humans are programable and you can either program reality or be programmed. Become an active participant in reality! Do it for yourself and for your loved ones. Help shape the future and what lies ahead for yourself and for the human race at large!
An example:
Its saturday night and you're watching a movie on tv, you relax. When you are relaxed, your filter lowers its guard and becomes more susceptible to subconcious messaging. Not only do the beliefs presented in the movie will pass through to your subconcious, but also when ads play during the break. You will be more susceptible to their intentions. Similarly, social networks. feed you content that can influence the way you act and your desires. Their algorithms is made to keep your attention and direct it. If a company or a goverment pays them, they can start feeding you content that will promote views benefiting them or that will influence your decision making.