IME, restraining the lo, no matter how gently, backfires and only makes the situation worse as they get older. Dipe changes are still often a challenge for us now at 22 mos, but DH and I just keep drawing on every ounce of creativity we can muster to help it happen. (I am one who cannot stand leaving my little one in wet dipes at all and prefer very frequent changes too.) I have succumbed to the restraint methods more than once and have regretted it immensely, not only for how wrong it feels afterward, but then dd started crying as soon as we said the words 'diaper change'.

At about 10 mos to 17 mos or so (give or take a month), we would give her toys or books to play with or 'read' and she would be distracted by that long enough to get it changed, snappied and all. I also engage her in the process- have her hold the fresh dipey or the wipe or get her cover off so she can feel the wet diaper (we use fleece liners, so I don't think she feels the wet as much). I talk to her about it in words that make it fun and playful. Or as I tell my dh, you gotta 'sell' it to them- make it sound really fun and exciting, like a trip somewhere to the magic fresh dipes.
Lately tho the toys and books aren't working as much, so I'm having to get even more creative with the use of stories and talk to her more about the fabulous fresh dipeys waiting to hug her. Just recently she's exploding with words and sentences and she cracked me up yesterday when for the first time she says, "fresh dipe! fresh dipe!"

It still isn't always smooth sailing, but I think it helps me to remember that's because she is her own person who is discovering her own wants, needs and preferences and it's my job to meet her halfway, not force her to do what I think she should.