George,
It's a fantastic tool. Hard to believe all these little bits come together and do a job so well. Rather than try to explain the assembly, take a look at the pictures. The pictures are of wheel bearing removal but the concept will be the same for the swing arm. Once the tool is relaxed, place it inside the outer race so the screw heads extend just past the race. Tightening the center screw pushes the interior nut head spreading the screw heads outward to capture the race. Continue tightening with the nut on the center screw with the outer spacer and the race is forced out safely. You'll get it figured out once you get started. Hope these help.