You don't. You will have to produce the password---you can get help with password reminders from Apple. If not, you can produce the original receipt.
Outside of that, there are a zillion shady companies out there that will take your money to help you launder a stolen phone. There is no well established long lasting solution--at any time you can lose the activation unlock--if you are able to get one--when Apple updates the iOS.
This really is a dead end.