These gas tanks are pretty thick steel. Unfortunately I don't think anything short of an actual repair will be an option. If the paint is already cracked around the edges, that's a pretty sure sign of having to repair, fill, and repaint. Paintless dent removal might get it close, if it can be accessed, but it'll never be perfect. Whatever yo do, don't drill holes in it to pull it out. Chances are it'll never seal properly again. A stud gun can tack weld a stud to the tank so you can use a slide hammer to pull it out, but that requires grinding it down to bare metal. Sometimes you just gotta bite the bullet and do the repair. Today's body fillers are wonderful products. That dent's not so deep you couldn't just fill it and repaint it. If you're careful and mask the stripes with several layers of tape as you do the repair you might even be able to save the stripes and just repaint the red followed by clear coats over the entire tank afterwards. As a painter, I think that would be the best option in my opinion. Good luck with it,