1997 c1500 Ext Cab third door issues

I have a 1997 C1500 Chevy Silverado Extended cab 5.7L V8 2WD and there is an extreme amount of wind noise in the cab, mainly from the passenger side with the 3rd door. I was studying it and noticed that when closing the passenger door, it seems to bounce on the third door like the third door isn't completely closed. It used to be stuck but when I had my stereo system put in they fixed it. The guy said that all they did was pull it really hard and it opened...sounds like they probably damaged it. What my guess is is that the top latch for the third door needs to be tightened and I have no idea how to do that. Any ideas?