You can do it without removing anything. You have to depressurize the coolant system by loosening the cap. This will allow you to flatten the hose enough to slide the filter by. I usually do take the booster hose (the hard plastic line) loose to give more room. The black rubber o-rings go on the bolt that holds the filter on for seals.
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM