Seat belt trapped my kid in the truck

[Wgesnerjr]

So we went out today to buy Christmas tree. It was me driving my daughter's boyfriend in the passenger seat in my daughter in the middle. Were all buckled in going along just fine but when we got to the tree lot, the seatbelt would not release for the middle seat and my daughter was trapped in the truck a. We jiggled, we moved, we messed with the button nothing would let go. Started to think I was going to have to cut the new belt webbing to get her out. Finally after a lot of tugging and pushing and pulling the belt released. So I have come home of tried to lubricate the buckle with no luck it still sticks.

How in the world do you get the belt buckle apart so you can check the insides?

Last year I paid a lot of money to have all the seat belts rewebbed. I really don't want to have to replace the buckle but if that's the only way I guess I'll have to do it.