Popping out an "oil can" on a roof panel has nothing in common with fixing creases and dented sheetmetal.
Metal finishing at this level isn't something where you go out and buy some hammers and dollies and then it all magically happens like these pictures and videos, it's a skill that takes years to master and these guys are obviously pros.
If you don't know what you're doing you can do a lot more damage than good and wind up with a part that won't even fit back on your vehicle.
Proceed with caution.
