Sealing up my transom
 

I have done some pretty extensive work with fiberglass in the past.....I have built some pretty trick and custom subwoofer enclosure that were made out of 100% fiberglass.....and they have never broke, cracked, or otherwise got messed up...

Since I have some fiberglass experience how hard is it to seal up my transom? Is there a process or step by step on what I need to do?....

Glass Dave can you make some suggestion here?

not very. especially if you have experience. i have done quite a few with good success from a structural and thoroughness standpoint. the one thing i did do which may be overkill or xtra work was to cut the inner layer of glass and wood from the inside of the transom as to help diminsih any defect due to load.
are you raising the x-dimension or going to a differenet type of drive, because say konrad to bravo or #6 or 5 over bravo you can just cut over exhisting hole in many cases and avoid the work