All - Did this change yesterday. Taking it apart was a job because the intake air plumbing for the ISL is in front of air dryer unit. Also forgot my 15MM socket, and had to use a 5/8" instead which is very close. Cleaned up the area of the unit where the cartridge cover goes, the cartridge cover and wiped the whole thing down good with cleaner and clean towels. Taking out the old filter (was covered in oil) was not a big deal, putting in the new filter also was not a big deal, went right in, turned and locked into place by hand, did not need to push down as drawing shows. I did have to take apart the incoming air pipe for the ISL since that 8" pipe was in the way of seeing how the O-ring went back onto the unit. Good thing, found a clearance light lens inside the air-filter housing, how that got into that space is a mystery. I am not missing any lens covers, so I think someone threw it in there. It was stopped by the air filter so no damage done, but today, I am going to remove the AF and clean out that compartment prior to starting the coach and again making sure I don't have issues with it. Then reassembled the incoming air pipe, which was not too bad. Glad this job is only about every 5 years.
Monty & Janet - 2007 Alpine APEX 40 MDTS
S/N - 75715 - Retired - Master Certified RV Tech