Easiest way would be to glue the Velcro at a right angle to a strip of material (either PVC or hypalon, depending on your boat construction), then glue the material horizontally to what remains of that patch.
Remove the patch and sew up a new one, then reattach it. I changed oars from the thinner Zodiac oars to a decent plastic oar with an aluminum handle. Doing so required me to make my own mounts, and remove the old ones. Just kinda copy what is there, and make it however you want.
