Sorry for such a basic question, but what is the procedure to remove the upper playfield? I need to replace one of the lock bulbs. I see two thumb screws in the front and I think there is a third one, but don't see it. Do I need to lift the playfield to get to it. Once the thumb screws are removed does the field lift right off to give access to the bulbs? Thanks

Just got around to doing this, a bit of a PIA. I loosened the three thumbscrews and lifted the playfield while tilting it back. It's a very tight squeeze to get your hand in there to pull out the 555. After about 15 mins of wriggling, finally got it out and replaced it. The monitor wires had enough slack in them that I didn't need to remove the connector. Didnt need to remove the backlights either. I think to really get good access, you might need to remove the back of the playfield so that you can tilt the mini PF higher.