The manual tells you how to remove the side panel. No big deal. Pay attention to detail so you get the cowl seal back in place properly.
Not sure if this will work for you but.. On my 175's I "Cheat" just a bit.. I don't pull the pans off anymore. Now that I know where the seals go and how they are supposed to seat, I just move it about 1/2" away from the motor and I can get my filter out. Grab a plastic bag and slide it around the filter to catch the oil that will try to spill as you spin the filter off.
One trick that I am going to try is to put a small tab of "Duck" tape on the motor just under the drain so when I get down to the last bits of oil it will follow the tape tail down to the pan vs covering the anti cav plate.