Easy as pie. I did the factory 20's on my Ram with about 2-3 cans. I'm not really a fan of the black rim look, but figured I'd try because it was cheap. It wasn't a walk in the park to take off, but it wasn't that bad. No permanent affects so even if it does take a little time to remove, it's not like it hurts anything.
Also like michiganpat, I did the pockets on my '10 SXT. Not bad, but I wasn't happy with the lines, so I peeled it off. It came of those pretty easy. I'm not sure what made one harder to remove than the other, except that maybe because I had it on the Ram rims longer.
Either way, it's easy to do, doesn't cost a lot (even if you do use 5 cans), and is completely reversible without any negative affects to the rims. Certainly worth a shot.
Here's the rims I was referring to.