Phoenix slick 580 60cc . How to install horizontal stabilizer servos ?
 

I have read the manual over and over and still can't figure out where to install elevator servos. It shows to install inside them but there's no mounting block to screw into. I tried installing them on top but the wood is to thin and doesn't seem right. This is a brand new arf and I don't know what to do.

Pgs 14, 15, 16 are very clear the servo goes into the root of the horizontal stab. What part of the picture is hard to understand?