I read the thread from the above link. Reading it chilled me to my bones. It scares me to death to think of one of our mercedesshop friends holding a screwdriver under a belt while someone elses BUMPS the starter. This engine can very easily start and if it does, who knows what could be the result.
If you can't get any belt off, most likely you have not looked hard enough and long enough to find the necessary bolts or whatever that need attention for this operation. If you can't find them, get some help. I have never seen an MB belt on any device that could not be loosened and tightened with tools. You may find half your wrenches, sockets, extensions, ratchets and breaker bars scattered around the car before you're finished, but it can always be done with persistence.
Please don't take such a risk! If you get stuck on something like this in the Dallas area, let me know and I'll come and try to help before I'll stand by and see someone get hurt.
Be safe and have a great day,