1. Cut a small - 3 by 5 - piece of 1/4 inch plywood and epoxied to the fan hub . Right now the epoxy is the only thing holding the LED assembly to the fan. Perhaps some wire ties for safety would be good. I think I will add them later.
2. I cut a 15 by 2.5 inch piece of plastic from some stock I had. Sheets of plastic can be had at Home Depot. I just guessed at the size and it turned out to be pretty good.
3. Drill 7 holes in one end about 3/4 of an inch apart for the LEDs. I found a drill size that allows the LEDs to be pressed into the holes quite tightly. If they had not fit nicely, I would have used a dab of hot glue to hold in place.
4. Insert the 7 LEDs into the holes.
5. Attach the plastic to the 3 by 5 plywood with small wood screws.