Install the ca hinges as stated above. They should be about half in on each side. If you are installing ailerons shove the hinge half in the wing and half in the aileron. Put a pin in the slit as to space the aileron slightly ( small pin width ) away from the wing. Make sure you do this for all the hinges for that aileron. Then put a drop of thin ca glue in the slits. I put them in top and bottom but usually it's not neccesary.

If you have a problem centering hinge, just put in the one side and ca glue it in place then put in the other side and ca.

This is the method i always use and no problems yet.

hope this helps