You'll need to remove the frame on 4 of 6 panels. Save them though, they'll be used again in the next step. Also make sure to hold on to the screws.
You only need to cut 2 of the 4 frames, but keep the extras as a backup.
A 4-40 1/2" zinc screw, oval T-nut and 1/16" nylon spacer provides just enough room for the extrusion to slide on nice and snug. I didn't have any 1/16" on hand so I cut down a 3/16" nylon spacer using diagonal cutters.
Prepare 8 of these.