Like I said---chapter 24 page 3. If you have the plans, you have this page---this is the last page of the Wing and Winglet Assembly.
Soo....here it is...
"Drill through the wing with a 1/4 inch bit, in the position shown. This hole is foy your wing tiedown. The tiedown hardware is kept in the cockpit during flight an is installed when you need to tie down."
The picture shows 1" from the trailing edge and 2" from the max thickness of the winglet.
I used an I bolt with a wing nut, wide area washers and rubber grommets.
It seems kind of strange that the hole is that far back----but what do I know, I am not a Varieze guy.
In the longez, you flox a aluminum tube in the hole that you drill. Here is what it says about the longez...
Drill a 3/8" hole through the wings, 13" inboard along the leading edge, and 9.5" aft of the leading edge. This will assure that you do not drill through the shear web, but will be just aft of the shear web. Now flox a piece of aluminum tube into each wing, so that the tube is flush with the skin top and bottom. 3/8 OD x .049 in 2024T3. Obtain two AN4 bolts and make up a couple of removable tie downs as shown, these can be stored in the center-section spar when not in use.
Hope this helps