Changing diaper with sleep sack

Raven
Ok question. How does everyone change their baby in the middle of the night while in the sleep sack. It's difficult to get the bottom open and up high enough to get the diaper all the way one. And my LO likes to squirm a lot. And if I undo the sleep sack the Velcro is crazy loud and makes her really wake up. Thanks
*I guess I should add that I'm using the Halo sleepsack. But I like to hear other people's suggestions for what they use that might work better. I'm also trying to get her to sleep longer through out the night and on her own (been co-sleeping since birth).