RE: Deck Core Replacement Resources
Have a look in the archive section there is quite a lot of good info on that. Having been down that path myself I would throw in two points for what it's worth.
Firstly, make sure you know where the leak is coming from, could be a few places, and second point is test well north and south of the delamination to make sure you get all the rot.
It's not an overly technical job, but it is hard work and pretty messy.(especially if you step in the expoxy mix while triping over the Flaine tool you forgot to pick up!)