What I did
I just used a piece of .125" (made from one leg of an angle scrap) across the top and tied to the longerons if I recall. You just need to adlib a bit and be creative. Ultimately, they are just a hard stop to prevent the surrounding structure from getting wrecked. On another note while your in that area, make sure your empennage fairing is securely attached (good nutplates)at the AFT Lower end and clears the elevators , as there have been cases of the fairing screws migrating and the elevators being jammed. Se attached picture.
8A7 / Advance NC