Quoted from ChrisS:

I’ll be interested to hear what others say since I don’t know if I have read a proper way to do this.
I tip up the playfield and lift it straight up off the hinge posts. I then set the back of the brackets on the posts. This allows that extra space to get to the back in most instances. Also depending on GI socket placement you can slide the playfield out a little further, letting it slide and rest on the posts.
I have a broom handle prop rod I use for the excess playfield hanging off the front for the cab so it’s not resting on any of the mechs or wires. It just sits on the ground. If you are on concrete or hardwood I suggest a rubber pinfoot for the prop rod. That way it won’t slide while you work.
Unconventional, yes, but I’ve been doing cleaning and swaps this way for years.
Rubbers in the back are a PITA since you have to most likely take off the big upper ramp mech and form.