At the attatchment points of the horizontal stabs, there are some marks where you have to dremel out. Don't be afraid to make these oversize. Usually a tight fit is necessary but not here, it is alot easier to install and adjust when the fit is sloppy. also, dremel out a spot for the elevator control horn bracket before you permanently install the horizontal stab. I didn't do this and it was a lot harder to do then if I had done it before hand. Just read the directions and follow them to a tee on this part of your build.
I did a mock up install and tried the stab on one side, then on the other, taped them together, tweeked them here and there untill I was satisfied with the fit. This took along time, it just didn't seem to want to be straight!!! I finally got it and glued in one side, but you dont glue the spars to the fuse just yet, just the butt of the stab to the fuse.