I know this is an old thread but here's a sort of update on the process from my experience. I watched some Youtubes about doing the "glue on" puller operation and it seemed useful. One video showed a homespun attempt that I modified and used with success. So here's my El Cheapo method:
Take some wood dowelling or just scraps from 3/4" diameter to 1.5" diameter (approximately!) with one end cut square and all edges & corners rounded a bit. Make the wood pieces about 3" long, from stout material, not something soft like cedar. Drill a 1/4" hole across the block about 2" up from the end that will glue to the work. Use a couple of heavy Zip ties to connect the block to your slide hammer. A much better option would be to use a clevis type connection, but I was just experimenting.
BTW You can make a slide hammer with a long bolt like used for powerline work, or heavy "all thread" rod. Put a sliding weight on it with a nut and washer at one end for the weight to smack into. At the other end, you can make whatever connectors you need, held in place with a nut. Watch your fingers!
As mentioned in the previous thread, there's a couple of critical things, clean the work and heat the glue well. You may need to use a real wax and grease remover - more on this is a second. Glue on your wood block. On larger dents, it's usually best to work from the sides of the dent not down in the center. Trying to "get it all at once" is often too much at once. Let the glue cool thoroughly.
If the tank has been aired out, perhaps derusted so it's not wreaking of fumes, you can also heat the perimeter of the damaged area with a hot air gun. You can use a simple remote temperature sensing gun to monitor the progress - take it to about 150 degrees Fahrenheit. On a sunny day, just leave the tank in the sun for a few hours
Then hook up your slide hammer and give the thing a good wack. Note that you have to hold the tank securely when doing this with the tank off the bike. Sometimes the glue breaks away from the tank cleanly with no useful work done - this usually indicates that your glue did not adhere - probably the part was waxed well. Be prepared that you may spend hours, gluing on, letting it cool, pulling a bit - the progress is sometimes halting, slow but incrementally it's often useful.
I upgraded my slide hammer with a metal connector and I purchased a set of proper adapters from Amazon. Now, without the Zip ties, I figured I'd removed any stretching at the connection and so I'd get faster results. But all I did was succeed in breaking away the glue at the work, despite thorough cleaning and careful gluing. So I've ordered the high tensile glue from Amazon - eta two weeks. Pray for me?