I did ALL the holes on my 25 2 years ago- took off the hardware, and used an 1/8 or 3/16th allen wrench for the digger, after the nail just bent up. The allen wrench lasted for the whole job. I used thickened epoxy, slowly dribbling it into the small hole left by the bolt. Taping the backside is a must. I used 1/8th steel plate for the backing plates, very carefully drilling the holes to fit the original holes. I found that one of them had to be about 3 /64ths oversize for a little wiggle room, at least in the salon section. Installed the bolts, and halfway in we put 4000 on the threads , then pushed them all the way in.
Put a dab on the backing plate around the holes, put the plate up on the screws, then tightened them all down. Bomber.
The foredeck cleat was just bolted to the deck, so in that case I cored the deck, and used a 14" triangular piece of 3/4 " plywood epoxied to the bottom of the deck / V-berth ceiling then used the same sized piece of 1/8th sheet steel for a backer. The cleat isn't going anywhere.
It's a slow job, but we have NO leaks, and have utmost faith in the hardware now.
good luck!