1. Remove old venturi covers. The best tool is a thin razor blade. The glue to attach the drain cover from the factory is soft to make it easier to remove. Lightly slice between the boat and the venturi cover while being careful not to cut into the boat. This means go slowly and saw the razor blade with small strokes.
2. Once the venturi cover is off, you need to remove the old glue so that the new venturi will have a flat surface to bond to. Scraping with a razor blade is ok. If you scratch some paint off, not to worry but be careful to not cut into the carbon. Sandpaper also works well. Liquid cleaners like Goo Gone do not work on this type of glue. Do not use heat to remove the glue.
3. Once you have a clean surface, dry fit the new venturi covers. Make sure the open end of the venturi cover is well behind the hole in the footwell, the farther the better. Make a pencil mark around the cover. Remover the cover and place tape along the pencil mark to keep your boat clean from oozing glue.
4. Glue: Gorilla glue (water curing version/non-water curing version both ok) 30-minute epoxy glue both work well. You will also need some 3m painters tape for holding the Venturi cover in place while the glue cures.
5. Mix and apply the glue to BOTH SURFACES ONLY where you need to attach the venturi to the canoe: Do not fill up the venturi with glue!!! I suggest you use a popsicle stick or similar to apply glue to the correct place. LESS IS MORE in the step!!!!! You really want very little to ZERO ooze out paste the edge of the Venturi.
6. Once in place and glued, put tape over the venturi cover and hull with tension to hold the venturi down and in position.
7. In 1 hour come back and remove the tape and clean any ooze with a razor blade.
8. Make sure the hole from the footwell is not blocked by the glue.