IMO, definitely need the special tool to remove the lock ring from the rear of the hub. I used properly sized punches to get the races out with the hub in place. There's a collapsible brass piece that gets replaced and gets crushed when you reassemble..the special tool is needed so you can finely adjust the compression of the crush spacer ring using a breaker bar on the tool..too far and you've got to start over with a new one. Instructions call for measuring tools/runout but if you put the tire and wheel on, you can wiggle the wheel and tighten the rear lock ring until it just snugs up (like adjusting the front wheel bearings).

MikeL