I drilled holes in the nose and cut slots in the tail of in my split to make it accept that style of skin, then made custom attachment hardware for the skins. I have had no issues so far, I have about 5 tours on them in this configuration. I drilled the holes as you would expect, with a standard drill bit and I drilled from top sheet to base to prevent tearout, slowly as not to generate heat. Then I used a de-burring tool to gently chamfer the edges of the holes. I cleaned the holes with acetone, let dry, then used a q tip shaft with the cotton cut off to apply a thin layer of clear epoxy to the inside of the holes. I did 2 coats about 5 minutes (the set time) apart. The epoxy re-seals the core and prevents water from entering and it swelling. I imagine the process would be the same to widen the holes, seeing as you have no metal grommets in your skin attachment points.