I always leave shit in the cabinet and have to open the game back up and lift the playfield to retrieve it. A telescopic magnet, a claw that grabs things, and the magnetic trays that hold your parts are your 3 best friends.
The best thing about working on pins for me is i am a dumbass so i make about 300 trips from the game to my tool box and back because i never have the right tools. It gives me a great workout.