The RS-17 that makes up the trailing edge needs a 45° angle cut on the back side. To use my router I stapled the top and bottom together so the router bearing had something to ride on.
Next I cut the ribs to accept the trailing edge. This was not real simple because they needed cut behind the notch in the plywood rib gusset.
After cutting the piece to length I put it in place so I could mark where I need to put glue. I also put wax paper on the aileron to prevent glue from dripping onto the aileron.
I lined up the ribs with the aileron rib then stapled the RS-17 in place.
Here you can see that the 45° angle is not quite enough to provide good clearance for the aileron to freely move.
A few passes with the hand plane resolve this issue.
After planing the angle of the bevel ends up being about 30° not 45°.
When I flipped the wing over to install the trailing edge on the bottom of the wing I used some clamps to keep the wing from rocking. First I clamped a few large clamps to the workbench and rested the rear spar on them.
To keep the wing from sliding off of the clamps I used some small clamps to hold the spar onto the large clamp.
This held the wing vary stable but did put the trailing edge a little high.