Oh, I meant to throw on a couple of photos of what your fuel pump and filter look like inside the tank. This is from my 1100RT but is identical to my 2001 1150GS (same part numbers and everything):
Tank emptied and removed (the RT tank is plastic), mark corresponding lines with tape or something so you put them back together correctly:
Coming out, be careful things don't get hung up:
The Gizmo. The little internal lines can degrade, check them carefully or better yet, just get new ones and replace them. The "U"-shaped one comes pre-bent from BMW, you can't make a bend like that with hose from the auto parts store.
I've also had to replace the fork seals on my GS, just a wear item from all the dirt roads I guess, and that was not very difficult either. All the suspension is done by the telelever front end, so the fork tubes don't even have springs or anything in them, just oil and damping valves, very easy to clean and service. If you do remove the seals, remember that they have a top and bottom, don't get them in upside down or they'll leak. Don't ask how I know this
. I've got photos if you're interested. I was amazed at the amount of dirt, water/oil emulsion, and bug parts in the fork oil, so I put some rubber fork boots on when I did the job and haven't had any seal issues since.