I have just completed replacing the main input shaft seal and clutch assembly on my '05 R1200GS with 54k. using this thread. It went without a hitch! I was seriously overwhelmed at the scope of the project before starting, however, after about an hour into it, I realized that it simply was a series of minor procedures - disconnect shift linkage, side stand switch, rear wiring harness, etc. It was way less daunting after that realization. I was amazed that there were so few bolts in the tray after the split. It took 3.5 hours to get to the clutch and took equally as long to reassemble. The cleaning, however, was super time consuming as gear oil makes a sticky mess.
Thanks for taking the time to create this well illustrated how-to.