I don't like to use tape, but I do use a variant of the Paul W (Jingle Jangle) method for the 12-string. It goes by pretty fast; I also bend the ball end of the string (it's a good idea for any slotted TP, or Bigsby, btw). I generally use a capo for the 12 string, to hold tension on the string and keep it from falling out of the slot when I wind it.
The last time I changed my 12-er with an R TP the process went by fairly quickly; it doesn't take that long; I think I did it in about 30 minutes or less start to finish, while chatting away with a guest. I think Paul W's record is 18 minutes, or slightly less.