When applying tape over tape the bellows get thicker and the bellow straps will no longer close.
It is best to peel off the old tape. Normally about 80% peels of like Jim said. The other 20% will be a pain in the...
After you got most of it off, apply 24m tape, and the bellow straps should still close properly.
By using 24mm tape any damage to where the "end" of the old narrower tape was will be covered and thus invisible.
When gluing on new tape, put strips of plastic (old transparency film) in the folds so that any glue that oozes out sticks to the plastic and not to the adjacent bellow fold.