Per the book I temporarily attached the H-beams to the top of the canard to align it for skinning the bottom. The H-beams were a little short so I sourced some 2"x2"x8' aluminum angle from Lowes and attached it end to end via carpet tape to one of the H-beams. That gave me enough length to properly lay up the trailing edge of the canard.
To properly place the other H-beam from the leading edge (it is ok that it is short because it it just used to make sure the canard is flat) I made a mark on the canard jig and pushed tooth picks in the foam in about 6 places down the length of the canard. Then set the H-beam next to them, thus properly spacing it.