My spoiler had been dislodged somehow but was intact. The adhesive strip does NOT come off with a heat gun. Elbow grease and patience.
The Chevy dealer did not have enough of the 7 (me thinks) clips that attach the spoiler to the tailgate. They had 2 at $6 each. I found some on Amazon and a box of 100 was 25. If anyone needs a set, PM me. I'll send you 10 for $5 including postage.
I used a good 3M adhesive strip and the clips and it's as solid as day one.