I did one way back when, it was a warranty job as MB warrantied these to dual chain. It is a pain in the rear, you have to remove the front panel (forgot the correct term) of the car, water pump, alternator, powersteering flywheel, all the raills and sprockets about 10 hours in labour and parts where highish about $400 back then (late 80's) when I did it.
Do not think MB will still honour the warranty though might be worth a try.
By the way I would also recommend you do it though.
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)