an experienced tire person can dismount a tire from a rim in about 2 minutes, if already flat, 1 minute.
Fixing a flat with the only accepted way by me, with a patch can take 15-20 minutes with some time to cure the patch glue and test the leak in a water tank(yes this is what I used to do in the shop)
and then remount the tire 2 minutes... done,
so about a half hour, thats if the shop isn't too busy, and if you carried the tire in, if you have your car, usually it'll take longer for a walk in appointment.
