I previously marked the location and alignment for the vortilons. Following Malcolm’s advice, I marked the outline of the vortilons and then masked the wing about a 1/4″ larger than the pad.  I also masked the top of the vortilons.  This will eliminate a lot of cleanup afterwards.

Then cleaned the wing and vortilons with alcohol. Next I applied a layer of clear silicon adhesive to the vortilon and placed it in position. Then I used more masking tape to hold them in position while the adhesive cured.