To be honest i just go with him to save the stress!. I change him upstairs in a smallish space on the floor, i get his trousers off and undo his vest while he is playing. Then lie him down, sometimes he will stay for a second or two, sometimes not. If he doesn't i just wipe his bum while it's in the air in crawling position (easier than it sounds).I also put his clean nappy on while he is standing up holding on to his cot, takes practice but very easy. So bum clean with no stress for me or him!!