Quoted from benheck:You can remove the pasteboard bottom to get at the underside of the playfield. It's just as uncomfortable as working under a car, probably more so since you have to reach up.
If I had to work on one of these, I'd take the legs and backbox off (appears easy to do), then set the cabinet on it's side on a sturdy table. Prop it up a bit and open the glass panel, and you can easily get to everything.