Suspender ends clip into the (top) grommets on the cartridge or pistol belt (Whatever youre using).
Place canteen inside cover. Thread the wire bit into the bottom grommets wherever you want it.
Same for first aid pouch
Musette bag top straps clip to the metal D-rings on the suspenders around shoulder height. secondary suspender straps clip to the bottom of the bag.
If this helps.
This looks like a marine impression but the concept is the same.