Hi, I did mine last fall and I will try to explain as well as I can remember.
I did find instructions by searching on this site somewhere, but I cannot find them now.
There is a panel inside your left rear compartment where your power cord is. If you remove this panel you can get to the clamps that hold the filter in place. I found it easier to remove the intake and out flow clamps with the mount clamps loosened. Make sure you clean the rubber attachment points before you remove the old filter as you don't want any dust getting into your engine. Once you remove the clamps you can wiggle the side hose off and pull the filter down to remove the upper. When I reinstalled, I rotated the clamps to make it easier to get to the bolt heads next time. When originally installed by Freightliner, there was no motorhome on the chassis, so it didn't matter where the clamp bolts were located.
It only took me about 30 minutes, and was not all that difficult. I did find a couple large pieces of masking paper in the old filter.
Good luck, and happy traveling,
Mike