As mentioned by Sydney, a cone wrench is mandatory for holding the bearing cones. And you'll need a standard wrench to fit the locking nut that bears against the bearing cone. You must hold the bearing cone with the cone wrench when you loosen or tighten the locking nut. I have not looked at Park's hub instructions, but I trust it is complete. I've used their site for many repairs and their instructions are pretty decent.
To make this post controversial, we could segue into the "best" grease to use.
2003 R1000 CDale, 2001 Fuji Team, 2008 Surly CrossCheck, 1973 Schwinn Speedster, 1946 Hawthorne, a fixie, a broken tall bike, and an unsafe chopper.
Just this week I rebuilt my hub, a shimnao 600 that was 16 years old. Ploped in new bearings without a problem. You will need a cone wrench, mine was 15mm, and an standard wrench, mine was 17mm for the locknut.
Tensioning it was not too bad. The directions on park's site are good. It rolls better now then it did before.
and to add some conterverial topics, I user park's polylube 1000 for the grease.