I never thought it was EASY to change valve and seals. the parts don;t seperate that much to get the gaskets in properly. Some have suggested olive oil in the water to lube the shafts. Some makers of toilet treatments say they help lube the valves. I apply silicone grease to the shafts while in the dump mode and work them in and out. I find that use works better than anything. Dump more often or have a cap on them and work them . I find that if the valves are covered in water they work better then if you completely empty the tank and leave it empty.