I put mine on a T-shaped bellcrank mount - pushed through a slot in the fuselage - when it is to be mounted externally. Make sure that you cut the T long enough to account for the width of the fuse and whatever clearance you will need for the bellcrank you use. Test fit everything before gluing the T in --
Cut The Slot before gluing the wing in!
This drawing is a top view of the left wing - if the bellcrank is to go under the wing, make sure that you push in through the correct direction (I speak from experience!
)