If your wingtips already have corner light bays, or if you’re prepared to get the Dremel out and make some, you’re in luck!
The Original kit option called W415FG is a kit that matches up with a fiberglass corner light bay mod kit that was once supplied by a boat parts manufacturer.  This light bay has an opening of 120°.
The Original kit option called W415RA suits a mod kit that Van's once offered long ago.  They had metal parts that you riveted into the wing to make a light bay and a cover lens to suit, which ended up being just big enough to fit your typical Whelen position/strobe light.  This light bay opens to 90°.
The Flyleds boards are the same size as the original metalwork, so it's actually just as easy to cut a light bay and bond in some simple tabs made from either scrap aluminium or fiberglass to hold the Flyleds kit.
We have had the clear lenses re-made by the original manufacturer using the original molding piece.  Due to the shipping size these are only available from our distributors Flyboy Accessories in the US.  You can buy the W415 kits from them too.
Information on the Van’s mod kit is available to download on the Info page of the Flyleds website.
There is a picture of the 90° kit on the product page, but we think the installation could look a whole lot nicer than the example shown.  It's a very low sales volume kit for us and no one has offered any better pictures (yet!).
Another option is to buy or trade your wingtips to the later model W-715 "Batwings" or W715-1, either second hand or new from Van's.  There is a market for your older wingtips!