After trying several ways I took a piece of 1 by 4 scrape oak (any piece of wood would work) and drilled a 1 1/4 inch hole in it and used 3 small finishing nails at 9, 12, and 3 O'Clock to hold the strike centered over the hole, then I use a ball peen hammer and hit the center. Most times the ceter comes out on the first hit. If I could figure out how to upload a picture I would post a picture of the fixture.
Walt