You're correct. I had to go in through the bottom of the fuse. I stripped the covering from the last three bays on the bottom and also from the front of the stab to the rear of the fuse. I then made some patches to fill in the two servo holes and mounted the bell crank just behind the stab leading edge. The crank can be adjusted a little, so it isn't real critical where it goes. I used a CF rod to go from the crank to the servo, mounted on rails just behind the wing tube. The rudder servo is mounted there, too with pull pulls exiting the fuse in the last open bay under the stab. I put some pushrod guide on the pull pull cables where they exit the fuse to prevent rubbing on the ply back there.

Now, the hard part is trying to find the correct color of covering material to patch the fuse! Mine doesn't match perfectly, but it's close enough that it doesn't look bad from a few feet away. I figured since it was under the stab, it wouldn't be seen much anyway.

I think it's a worthwhile thing to do. This was the first time I've used the MK bell crank, but it wasn't too bad and it assures you of having perfectly matched throws on each elevator. Plus, you'll get a good laugh at the instructions. I love direct Japanese to English translations!