There is a little 20 buck thing at Auto Zone that hot glues a rod to the dent then you screw it out and it pops it. I got mine 1/2 way out that way. Never did get it all the way gone. Tried heat and dry ice but the metal is too strong at the shoulder area of the tank. Tried to PDR guys but they cant reach it do to the frame hump in the middle of the tank. Their tools would not reach far enough in.
You will probably be in body shop mode after playing with it for a while. A body shop may be able tack it to pull it out. Then just touch up and clear it.
