Step 1: First the Studs
Of my vest I used a studded belt because I couldn't find any studs.
Step 2: Adding the Studs to the Vest.
The studs have little prongs on either side of it. You push the prongs into the fabric and to the other side. Then you fold them into each other. That holds them into the fabric.
You can do what ever design you want. I did a simple thing.