You'll need to take the sunroof apart partially to figure it out. Unclip the 'bellows' type guards in either side. Behind this are two torx bolts on each side that you will remove, then you can lift the glass out. You will be able to get a closer look at the mechanism and figure out the problem. I had to have the rails replaced several months ago because of a horrible rattling that led to the mechanism breaking completely.

As for your other question, you'll need to remove the ECCM (electronic climate control module). Put the shifter in D, lift up the rear edge of the plastif shifter surround, and pull it out. Remove the two screws holding the ECCM in. The top is held with spring clips. It will take a fair amount of pulling to get it off. DO NOT unplug the ECCM as it will trip the SRS diagnostic sensor. I'm not sure how you change the bulbs, but it's likely they're proprietary and will need to be ordered by your dealer. You should be able to figure out the ECCM disassembly.