Marked area to be cut out after stabalizing with 4 more rivets.

Reason for installing rivets and nutplates before cutting is on other two insert cutouts the layup done by Europa, (or their vendor) was not stuck very well and it easily delaminated. By installing rivets and nutplates first it helped preventing some of the delamination and stabilized what was delaminated. I did put a little resin in there first and tried to scuff, but it is of poor quality where layup went onto wood.
This lower port insert area appears to be bonded the best, (comparing to Port and Starboard larger insert areas) onto the wood insert. Alan used a Perma-Grit cutter on Dremil tool to make cuts quick and fairly precise.