G.♣.
I usually changed them standing up.
For a pee diaper you can pretty much take one off and put the other one on. They don't need much wiping, but I always tried to do some.
For a poopy diaper I had them turn away from me and said, "Touch your toes!" They thought it was cool and would reach down and touch their toes. Then I would wipe. Sometimes I needed them to do it again, but I usually got most of it with them just doing it once. Then I'd turn them around and say, "Spread your legs apart," so I could put the new diaper on.
If you really think he's playing games with you then consider making it into a game. Think of a fun reason for him to do what you need him to do. Diaper changing time can be fun time if you are careful.
And I disagree that you need to start potty training. Neither of my boys were potty trained before 3 1/2. I thought I had my youngest potty trained earlier, but then he regressed. You can try it. But don't be too upset if it doesn't happen.