Ok. Installed the front fender extension. Worked out perfectly. Here are some details.
Electric drill with 3mm bit (3/32" works, too)
Tube of GOOP brand adhesive. (Don't use silicone sealer. Use GOOP. It'll glue a piece of plastic to a sheet of glass, yet remains flexible. Handles temperatures well, too.)
2 C-clamps with about 3" throat.
Scraps of cardboard to protect finish
Dremel tool with small grindstone
First remove front fender. 6 bolts, wiggle it out. Easy peasy.
Degrease/clean the inside of the rear of the fender with denatured alcohol. Test fit; remove any flash at seams if necessary.
Notice the mold even includes a couple dimples to clear the two small raised areas inside the OEM fender
Apply GOOP and remove protective film from self-stick tapes
Carefully put the two parts together, double checking alignment. The curve of the two pieces may not match perfectly, so press them together well to close any gap at the inside joint. Drill pilot holes for the 4 stainless screws one at a time, installing EACH screw FIRST before you drill the next hole, and do the *center holes first*. Then add a nice bead of GOOP at the inside joint. Moisten finger well with saliva or water and smooth the bead. Don't worry about a little excess glue on parts. After it's dry, it can be trimmed and/or peeled off, leaving no residue.
Now carefully apply a couple C-clamps to really squeeze the parts together. Use pieces of cardboard on the outside to protect finish from marring. (An extra pair of hands helps with this step!!)
Allow adhesive to cure for 24 hours or so. Then remove clamps. Notice screws protrude inside and are quite sharp. I used a Dremel tool to remove most of the tip, leaving a couple mm protruding for security.
Reinstall fender with 6 original bolts. Job done!!