While I think it is true what a pp said about the school working with her, this is what I'd do with ds, 4, at the beginning of the school year. He also had no interest in dressing himself:
With socks, I'd tell him, "I'll do one, you do one". With shirt, "I'll do one sleeve, you do the other sleeve". Same with pants, shoes, etc. Eventually he just started to do it himself. He somehow learned how to zip his jacket, because I never taught him - it must have been his M. directress! Ds also rebelled at first, but once I told him we'd do it together - teamwork - he was satisfied and then just started doing it himself. I make sure everything is very child friendly - velcro on shoes, etc. so he CAN do it himself.
With the potty, I wouln't expect the teachers to wipe a BM on a 5 year old, not to be insensitive but I'm being honest. I also do the "you wipe first, I'll help with the rest if you need it" approach.
Good luck! You have all summer to use the 'teamwork' approach!