I'll be finding out how to do this in a S124 shortly -- I suspect the proper way is to take down the center bearing after removing the bolts on the flex disk (front) -- should just give enough clearance to remove/replace the disk.

On the older models there is a nut under the rubber boot beside the center bearing that is loosened, allowing the front shaft half to push back.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!