Percocet is to be dispensed only to people with a prescription and only for a legitimate medical purpose. It is illegal to buy Percocet without a prescription, and it is illegal to sell or give your Percocet to someone else. Doing either of these things is against federal (and most state) laws, and you can be prosecuted under both.
It would be irresponsible to offer advice about buying Percocet without a prescription without at least mentioning addiction. If you are searching the Internet for ways to buy this medication without a prescription, you may be addicted to Percocet. Your healthcare provider is a great place to start when searching for help with abuse or addiction. He or she will be able to help you deal with such problems (hopefully in a nonjudgmental way) or may suggest other resources for you.