a thread died for this.
a GPS spoofer, but to do that you need a rooted Android, a jailbroken iPhone, or an Android emulator. most android emulators allow you to change your GPS location at will, but you're probably (and I say with an 80% certainty) get banned for it.
As you'll undoubtedly move your location from one place faster than you could possibly travel to the next within a reasonable amount of time. I know this because you made a fucking thread for it, killing another instead of asking Pokemon Go General.
Next time look for a relevant thread instead of immediately making a new one just to have your one selfish question answered.
and no we don't know how to unban you for doing this, so it's all on you.