Problem with Driver side window

[SVXGIRL182]

A couple days ago, I went to roll down my driver side window and it just made sorta a pop noise and sounded like it was going down but the window didn't go anywhere. My b/f checked it out and he says its probably off the track since he can push the window up and down by hand. He was going to take the door panel off today and try and fix it. Is there anything special he should know before taking off the door panel? Any tips, tricks? He said it looks pretty straight forward..a couple screws and probably the standard pop rivets or whatever. Any tips would be appreciated.

Thanks