It is called Jailbreaking, but there are different procedures for each phone. Also jailbreaking does not come with out risks, that is that if performed incorrectly you can brick it to where its no longer functional again. However if you find your specific model and a procedure online with all info and firmware to do so and others stated success with that specific model, you can attempt it on your own. But I have heard of some models that dont have breaks for them or cant be broken for some reason or another.
