I use the Dubro Lexan scissor and reamer kit, $12.95 total.
Lexan scissors on everything except antenna and body mount holes, use the reamer for those.
I also use the reamer to start cooling holes for the windshield and motor then finish off with scissors.

I have to say, it takes a bit of practice to get precise with the scissors and I ruined a couple bodies learning.

Also, super thick bodies are better suited for dremel work, not scissors.