My Salem filter is in the same location. When I change mine, I put a bowl under the filter, unscrew the housing, then dump a little in the bowl. That way, the housing can be tilted to fit out the hole...where I can dump the rest out, and change the filter easily.
Pete (Jolly Mon)
2018 Wildwood Grand Lodge 42 DLTS
-Seasonal Space, Northern MN.
-2017 Sylvan 8522 LZ LES/115 Merc/Sea Legs