What's would be best way to cut a pickup notch into a floating ebony pickguard/fingerrest by hand? I'd like to put a Benedetto ebony fingerrest on an archtop, but I'll need to add a relief for the floating pickup.

I'm not quite ready to invest in a router or scroll saw or whatever yet (still slowly dipping my toes into guitar making). What would be the best way to do it by hand? Coping saw and/or files?