My step-son is building a 4* 40. I helped with the assembly of one wing panel while visiting him a week ago. I did my best trying to figure out the SIG Dual Tool. But he reports now that if he follows my example on the other wing half, that the dihedral will not match the angle on the dihedral brace. He says there is too much dihedral. So, I have two questions.. How do you use the dual tool to set the wing's root rib, and assuming I've done it wrong and set the angle too great, what's the best way to fix that? The spars and such have already been sanded flush with the rib.

Thanks!
John