Did mine last weekend. After reading many
posts on it, sounds like it makes sense to me. And I learned a few things, too.
1. There is a diagonal support brace molded into the CA intake side of the core support, about 2.5" down from the top inside corner(measuring down in the front), rather difficult to cut through. Obviously a guy is better off to stay below that with the top of his cut.
2. A sensor( I think its for ext. temp. if you have auto hvac) will limit the vertical height of the opening, a little involved to move, but there is enough slack in the harness. Left mine where it was, still allowed the opening to be roughly the same size as the mouth of the intake.
3. I used a portion of an aluminum soffit vent. It has heavy screening, its louvered, worked out well. The turbo can be heard from standing in front of the truck. Certainly seems to breath better.