I usually do it myself, but, if we have no kids in the house (which is almost never, but it does occasionally happen) my wife will do it and it's great. As she's pulling off my plastic panties she looks at my soaking wet diapers and says things like "You big baby! Look at how much you peed in your diapers!" I love it.
For those of you who want to experience having your diapers changed by someone else, you may try this. I've never done this, but used to correspond with another ABDL friend who once did. He was out driving around one day, enjoying being out in his diapers which were soaking wet. After a while he pooped them. After that, he said, he drove past a nursing home and decided to pull in, park the car, and go inside. He says he was scared to death but did it anyway. He went to the desk and told them "I'm sorry to bother you but I'm incontinent and wear diapers and have had an accident, but I have no more diapers with me. Might you possibly have one here that I can have?"
He said that they were very understanding and said "Yes we can help you" and led him down the hall to a room, had him lay down, and two nurses came in with a diaper, cleaned him up, and changed him. They put his dirty cloth diapers in a plastic bag for him, he thanked them, offered to pay (they declined) then left. He said it was about the biggest most scary but wonderful thrill he's ever had.
Me? I'd be too nervous to do that sort of thing. But for those who aren't, it's an idea...