Glue down the cockpit risers pieces. Mix up epoxy and mix in colloidal silica, cellulose powder or wood flour to make a loose paste-like glue. Brush this the riser piece and around the perimeter of the cockpit. Lay the riser in place. When you have all the pieces in place for one layer adjust the position so it is centered around the cockpit hole.
Apply glue on top of the first layer and on the bottom of the next layer and build up another lamination.
Two layers of riser laminations is the minimum. Three layers will make getting a spray-skirt on-and-off a little easier.
Coat the whole bottom of the coaming lip with a thick layer of thickened epoxy to seal it completely against water. Apply epoxy to the top lamination of the riser and then lay the lip on top.
Check the alignment of all the lamination. Make sure they are all centered around the hole. Check to see the butt-joints between the pieces in each layer are tight.
Add as many clamps around the coaming as you have access to. Keep checking that you don’t knock any of the laminations out of place. Align the tips of the clamps along the inner perimeter, over the riser laminations If you place the clamps too far out from the inner edge you will bend down the coaming lip.
Now, do your best to clean up any squeeze out. Run your gloved finger all the way around the outer edge of the riser laminations, under the lip. Use an acid brush to wipe off any excess glue onto the inside.