Ed is right. Follow that and it will work just fine. It sounds a little too much right now but once you do it you will see its pretty easy. Plus thats the best way to get two servo wings too work. This way if there is a prob then you have at least one ail working witch will get you back on the ground.

P.S. You really dont need flaperons on the omp 540. It flys great with no mix. Now if all planes fly like that i would be happy!