Been there done that myself.

The little clamp on top of the filter with the hose coming into it is the primary filter retainer.

Undo the bolt, lift off the clamp, unplug the hose, and the primary filter is like a little basket (almost like a swimming pool strainer) under the hose connection.

If you ingest air at this point the car will run like cr*p or even die on you...

If your fuel hoses are original, order up a new set from the dealer and change them out. You will need to pull the IM, it is not too difficult if you have a way to raise up the car (a set of ramps is sufficient). Also order the IM gasket and the IM to EGR o-ring as you will need to replace them when removing the IM. And don't forget the 3 sealing washers needed for the one hose that uses a banjo bolt on the IP.

You will need a T40 bit for your socket set, these are readily available at the home improvement store.

Do an "advanced search" on my user name and OM606, I have posted the details on this several times recently.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech