FULL KIT INCLUDES: BOTH WASHERS, BACKING PLATE & 2 RIVETS
Clamp the panels together using spring clamps. Drill hole through both pieces, centering the hole vertically, leaving enough fiberglass so that it will not break.
On the inner panel:
Use the fastener backing plate to locate the rivet holes. After you have marked the position of the rivet holes, drill the holes with a 1/8 drill bit. The backing plate is installed on the back of the inner panel with the 2 pop rivets.
On the outer panel:
The white plastic cupped washer is installed under the head of the stud. The silver split washer is installed on the stud once it is through the outer panel to keep it from falling out.