I have attached a few photos of the tail servos that I did on my Ultimate. Basically find the slot where the pull pull wires come out (at the tip of my finger in the picture) and use that as your starting point to make the cut out. Back it up with a couple of small pieces of hardwood glued to the inside where the servo screws will go and thats about it. Use 1.5 inch servo arms for maximum throw and remember your going to have to program the servos either with a programmer if your using Hitec's or with matchbox's if your using JR servos to keep them from binding. It's actually very easy to do and only took about 45 min to an hour to complete
. Hope this helps.