Here you have an Alice rucksack. Standard issue Vietnam-era ruck. Some people prefer them over the new MOLLE II rucks. The design allows one to pack heavy things higher up more easily than the new rucks. One bad thing about them though, is the closure.
To hold the top flap closed, you have to snake 1 inch webbing through this triglide-esque attachment. Personally I like parachute buckles, so I'm going to add those.
The waist buckle was broken when I got my ruck, so I'll be replacing that too. This won't be part of the writeup, it's just a side note.
Step 1: Acquire parachute buckles. These are just a couple bucks at a hardware or fabric store, or you might be able to salvage them off an old backpack. I had some in a scrap bin.
The way the ruck is sewed, you can't just cut the threads and remove the old triglides. This also means you won't be able to put these on the webbing the old fashioned way. The remedy this:
Step 2: Make small cuts on the rear of the buckle. You only need to do this on the side of the buckles that attach to the bottom of the ruck, because the top webbing will accept a stock buckle.
Step 3: Snip the triglide off. I used some compound snips I use for cutting chainmail, but wire cutters would work just as well.
Here's a comparison of the old and the new.
Step 4: Cram the webbing loop onto the buckle. I had to use needle nosed pliers to get the webbing through the tiny cut. That's a good thing though - The harder it is to get on, the less likely it will be able to fall off in the field.
Step 5: Enjoy! Simply snap your buckles together, and you have a slightly more modern ruck. And you can open it with a simple squeeze, rather than running loops of webbing through the triglide.