It's not hard.
PM me your regular eMail address and I'll send you a PDF this evening.
I made the PDF to assist the users that purchase my CW-Vacuum Head Project, and you will just modify the cut-out to accommodate his unit.
AskBud
I cut mine in place using a dremel with a cutoff blade in it.
Jaroot, that is exactly how I did mine too. I covered it with making tape, drew my lines and cut it with the cut off wheel and sanded it smooth, no cracks, no fuss and workes perfect.