Contact Bennett Marine customer service - they'll walk you through it, as we will too! I put my Bennett tabs on 12-years ago and have YET to touch them, tweak them, adjust them or re-fill them!
On the full transom 25' I have, all of the screws for the tab planes were into solid glass layup. I still used 3M 5200. I'm not sure of your hull, so hopefully others will chime in with details.
Just make sure to use the RIGHT size tap drill for the body size (not the teeth) of the screws. Drill any thru-hole for tubing/hose oversize and fill with epoxy from
www.raka.com (buy their $20 sample kit!) and then drill smaller hole for the size needed ...
example, 1/2" drill, coat and fill (duct tape outside) then drill for 3/8" to allow a 5/16" tube/hose to go through.
Adjust sizes for what you need to put thru the hull. Also let the goop of choice setup and DO NOT crank on them and squeeze them too tight before they setup .... !!!! ... or you will have a dry joint! Even though it took an extra day, I did my install one morning with screws secure, but not so torqued as to squeeze out all of the goop. I used fast cure and then did my final hook-up and testing the next afternoon. Zero issues.