Replace the balls (very important, Stern balls are not of good quality), wax the playfield, put mylar and other playfield protectors as you see fit, play the crap out of it.
I know these topics are specific to Aerosmith, but the question has been asked several times and previous threads have good pointers. E.g:
https://pinside.com/pinball/forum/topic/wtb-acdc-premium-2
https://pinside.com/pinball/forum/topic/nibwax-first
https://pinside.com/pinball/forum/topic/delivery-day-first-nib
...