I had two stickers on my visors. The top one had English and French, which came off very easy, and left no residue on the fabric and left a sticky film on the original factory sticker that was under it (that sticker is in English only).
I can't even get a finger nail under that second sticker! I'm a little scared of what kind of a mess it might leave on the visor.
I really hate those stickers though, I wish they had just used some kind of a tab thing like the label that sticks out of the glove box.
goo gone doesnt really do anything to remove the sticky on the backside of the stickers, i pulled one off (it left the residue) then i used a haird dryer on the other sticker and it came off fine. i took goo gone to the hair dryered sticker to see if it wouild even remove the sticky and it doesnt.
There are several places that sell metal plates that can be installed over the stickers to cover them up. And most places will engrave them however you want. Or I know a guy who does custom interior work and will re-cover your visors if you take them out and send them to him. Can even do embroidery on them if you want. Very reasonable prices on them too.