I alternate my oil changes. I change the oil and filter every 33 hours. I end up removing the lower cowling never less than every other oil change. Recently my biggest issues is observing the SCAT duct adjacent to the exhaust system on the pilots side. There are two hoses in very close proximity to the exhaust and so I like to check for heat damage, cooling standoffs etc. I purchased rubber play mats from home depot which I put on the floor under the cowling. I put protective covers (actually made out of old version of the play matts over my propeller blades as they are carbon and can chip or scratch. after removing the snifter valve from the co-pilots side exhaust cover and the air duct hose from the pilot side, I remove all the air cleaner fasteners then I’m ready to drop the lower cowling. It does take two people to guide it past the prop blades as I have a four bladed prop and there is just no position that clears the prop with out some maneuvering. After a few dozen times I’d say it takes thirty to forty minutes going off and about twenty minutes going back on. I focus on how much a shop charges me when they do this job. When I don’t have time or have recently dropped the cowling, I simply loosen the copilot side fasteners and reach in and attach my quick drain hose. You do have a quick drain don’t you? hope this helps
