As
@Timm R Oday25 says, There is a way to get there, you just haven't found it yet.
I really doubt if the pulpit and cleats are/were held in place by screws and agree that wood screws to a piece of teak fiberglass onto the deck is a mistake.
I had an 1982 O'day 25 and the stern cleats were held in place by 1/4-20 machine screws, which are bolts, not wood type screws. That area of deck was reinforced with 1/4" plywood sandwiched into the fiberglass. I would expect yours to be the same.
Look closely in the area of the damage and see if you can tell if there was plywood sandwiched in the fiberglass. You should do the same for your repair.
Try a search for videos of Ripped Out Bow Cleats or even How to Repair a Hole in a Boat Deck.
There are tricks for repairing that kind of damage without accessing the inside, I'm sure.
After you make the deck repair, you will want to drill new holes for the cleat, then add a backing plate of metal, resin soaked wood or heavy duty fender washers and through bolt the cleat.
My 82 had a removable panel in the v-berth that gave access to the bow area. You may not have a removable panel so you may need to cut an access hole in the forward bulkhead in the v-berth to gain access.