Two rivets hold each shoulder connector strap in place - along with an amount of CA glue, just for good measure and flush surfaces. The rivets are located at each end of the strap piece. A third rivet (middle of strap) was used to afix the shoulder bell to the connector strap.
I replaced the supplied 1/2" Velcro strap with 1.5" wide Velcro material. I have not had a slip of the shoulder bell since. This whole upper section simply slips right into place, like a shirt. Another HIGHLY recommended Mod, thanks to TK103.
You may also note I have my TK designation written on the inside of every piece of armor. This is inked with a Sharpee pen and is a great idea when you go public with a Garrison of Troopers. Before and after events, it is easy to get parts mixed up with someone else's gear.