Perhaps you will indeed have to do a full replacement, but check out this link first:
Damage control. Perhaps something less than full replacement will do. Please advise.
EDIT: Hmm, for some reason Gonzo's (not Sticky's) all-important picture showing his repair technique is not displaying, I hope it is still visible to others - if not does anybody know if Gonzo posted a picture of his rivited floorboard repair anyplace else?
Also Abby note that Sticky also replaced the rubber floorbaords with aluminum, which at least do provide a fair amount of strengthening on their own and may help or eliminate the need to do any further bodywork replacement, depending on where exactly the damage is and its extent.
BTW >I've dropped my scoot before I installed foot pegs. Nothing broke
I believe Funky Monkey does not own a set of UFPs but made his own footpegs.