I don't mean to be discouraging, but there's something important to note.

I'm currently taking in a 'tank' for a friend in the same situation [lost the beer belly], and just moving in the belt/buckles won't result in a proper fit. His seat measurement stayed the same, and his belly came in over 4 inches - that changes the amount of taper required dramatically, and is a pile of work.

If he weren't a friend, I'd charge him like crazy for it, because it's most of the way towards building a new kilt [only with the wrong lines already pressed in].


Now, that said, moving the buckles and belt [and yes, you can totally do it yourself if you try] will keep the kilt from falling down, and won't look terrible. It all depends on what you want. If you're trying to save money, try the simplest option first, and see if you like the results.