I happened to have a Molle pack that I have never used and I was fooling around with it. There are two squarish devices at the bottom of the shoulder straps that connect to a strap down to the belt. Well I released those and now I can't get the dang thing back together again. I push it together and the pivoting part cannot be pushed down over the inserted part. It's close to the edge but it won't go over. Is there some trick for getting this together again?