I had the Warrior Gear pack on a 64 frame and decided to put it on a Downeast 1606 frame. It is a plastic frame used by the Marines. I had to cut off a few of the ladderlock buckles and replace them with field replacement buckles I made myself.
I didn't want to cut the sewn straps, so cutting the buckles was the only other way. To replace the buckles, I simply cut a diagonal slot in the buckle where the strap attaches, right in the middle. This allowed me to work the sewn end of the strap onto the buckle after passing it through the frame. You can buy field replacement buckles, but I couldn't source them locally. Canex sells field replacement quick disconnect buckles, that work also, but take up more space. They have a slot cut in the female end of the buckle where the strap attaches.
One of my buddies also has the same frame(1606) and pack and he cut the straps and used triglides to hold the strap together after passing it through the frame.
I also have an Alice frame, and I did manage to get the pack on it, but I wasn't terribly happy with it. I followed the CPGear video to get some ideas, but you will have to do some trial and error.
Good luck!
-Kevin