Look below the TV at floor level - you will see two doors with two hinges on one side and one hinge on the other side. The water fiter and pump is behind the left-hand door. Simply remove the two screws from the single hinge side to accesss the water filter.
I installed a friction latch like is used on the other doors so I didn't have to remove the screws all the time - works great.
By the way, the sub-woofer is behind the right-hand door.
Rick & Debbie; Brandy, Dexter R.I.P., & Fritz R.I.P. (The Doxie "Kids")
2015 Jayco Pinnacle 36RSQS 5'er
2011 Rockwood Windjammer 3001W (Traded)
2013 Chevy Silverado 3500HD LTZ, 6.6L Diesel Dually; B&W Goose Neck and Companion 5'er hitch