I've been friends with this girl for a couple years now but now she says that she wants me out of her life cause we had an argument. I want to stay in her life so how can i get her to forgive me

Forgiving often takes time, and pushing it won’t make someone forgive you faster. It might be a good idea to leave her alone, as she suggested. Tell her that you are really sorry, and that your always there for her whenever she needs you. In my opinion , a good friend needs to listen, if she wants to be left alone, leave her alone. You have been friends with her for some years, so I don’t think an argument would ruin your friendship completely. She probably needs time to forgive you and think over it.