Telelever forks don't have a lot inside them but the early R1100S forks are a bit of an exception. Apparently to save fork oil weight, they had a spacer tube inside the leg, fastened at the bottom by the bottom bolt shown in the fiche. The tube, however, is not shown in today's fiche.
With the R1100S the fork oil volume decreased from 470ml per leg to 170ml. This tube may have been the reason, but when it was deleted from production the specified fill volume didn't change. Series production started in June 1998, as 1999 models. The 2000 models did not have the tube.
The problem is that this tube complicates disassembly of the fork, and plays a role in sealing the bottom of the fork.
Removal is difficult because the bottom bolt was installed with thread sealant. As soon as it loosened, the whole tube started to spin. Holding the tube resulted in the bottom end cap spinning. I removed the upper end cap and forced a socket down against the bottom cap to pin it to the slider, allowing me to remove the bolt.
Reassembly was easier because I used crush washers instead of the O-ring. This meant that the bottom end cap locked itself to the slider as soon as the bolt tightened up. I also did not use thread sealant.
On later bikes there is no tube and the slider is threaded for the bottom bolt, so none of this is a problem. In fact, it's almost never necessary to take the bottom bolt out. With the tube there, a lot of dirt was trapped in the bottom of the slider and couldn't be flushed out, plus the tube blocked access to the fork seal.