How can I get rid of a really bad shark tooth. pleasee help?

okay I have a really bad shark tooth. For all of you who dont know what that is... its when your adult tooth grows in behind your baby tooth. Your baby tooth stays there so it looks like you have two rows of teeth. These baby teeth are very hard to pull because the roots are not dead yet. My family cannot afford to go to the dentist so I have pretty messed up teeth. How can I pull this tooth out without damaging my gums too bad? Its not really wiggly but it still moves..slightly. Ive heard of the door/string trick and mostly all the others. I need to know how to get this tooth out now. anyone know how? I prefer something not so painful lol helppp please