Step 1, I found two 5/16” * 24 bolts and ground with a drill and grinder a nice smooth point with to mark the exact locations of the Cabin Pin Block holes. Step 2, I added the points to the fwd and aft pins and closed the door tightly. Then I turned he handle downward and marked where the pins intersected the cabin. This enabled the pointers to be used as a set of drill guides. Stared with a $40 hole and worked my way up to the required 7/16” hole. Step 3, As written I am not using the supplied Darlin (plastic) Cabin Drill Pin Blocks but I have purchased 4 very nice machined aluminum block Pin Guides from I Fly RV-10 . COM for about $100.00 including the very nice bullet ends that contains a small magnet in the tip to activate the reed safety switch. After fitting the aluminum block Pin Guides I have decided to mount then directly on the aluminum frame by removing the small thickness of the fiberglass Crew Compartment.
Time about 6 hours because of mounting the aluminum block Pin Guides and both doors.
Machined Aluminum Block Pin Guides from I Fly RV-10 . com