I used a small blok of wook with a hole drilled to mark the location for the corrugated conduit I purchased from vans. I marked each rib, then used a 7/8" unibit and some very long drill extensions to punch through all the ribs. It took some time and a lot of messing around, but I finally drilled all the ribs. After deburring and pulling the conduit through the ribs, I applied RTV to each conduit entry hole to hold the conduit in place and keep it from chaffing.
