RBacon's answer is dead-on. In a nutshell you're basically using the stab to smear epoxy onto the wood inside the cut-out in the fuselage. It's a little bit messy but as he said, alcohol and paper towels cleans it right up. Don't pout on the alcohol though.

Also best if you use slower epoxy - 30 minute is the best choice. Plenty of time to work and clean up and then check to ensure the stabilizer is aligned properly.

Edit: Sorry, didn't read down far enough to see that it's already a done deal.