Hi there. Be careful when you open the backglass door with the 2 glasses inside it is very heavy and puts a lot of weight on the wooden backglass frame as it swings out. I usually rope someone in to help me when I need to get the back glass out.
There are the 2 mentioned metal tabs inside the BB door at the top above the rear BG which you need to slide out towards you to give you the clearance to move the front BG up. If the guys are able send you a picture it will make sense. Good luck.
