The empennage fairing fits 'like a horse in high heels' - I once read this comment on VAF. I found this to be fairly accurate. Both the left and right leading side of the empennage fairing needs to be cut so the fairing can be lowered for contact with the HS. I thought initially it might be possible to use some heat and convince the fairing to lie in place, but after an initial attempt, I realized it would be best just to cut along the line along the VS and HS intersection to a point where the empennage fairing is in contact with the HS.
I plan to bond the piece back together with some epoxy and microballons mixture, then sand to get a smooth surface.