http://www.westsystem.com/ss/assets/...aintenance.pdf
This is a pretty good how to book for basic glass work
If i was going to do a transom, I d do skunk s pour methoud and try to address the stringers as well. To do that your talking about cutting off the aft section of the cap or total removal.
That link is not working, look in the link section of this site on the second page, bradford posted it under fiberglass repair