You can't actually fully "restart" and erase your silence/silences. But you can use the reset button at the bottom of your profile. This will clear your stats to 0/0, clear all your money you have out, allow you to change your username, and allow you to change your avatar. If you just want to appeal a silence, email support.
You can make a different account, but you need to reset and factory reset your phone. Disclaimer: A Thinking Ape Inc told me about this.