I mounted the differential in a vise. The experts said mounting the differential case in a vise wouldn't hurt it.
Here's a close-up of the original safety wiring, which isn't really a great job.
I cut the old safety wire off. Note that while cutting the wire, try to position it so that you grab the wire with pliers opposite the bearing to avoid contacting the bearing with the pliers. Contact of hardened pliers with the bearing rollers might cause damage.
I left two bolts loose. The ring gear wasn't coming off anyway, but just to avoid a nasty ring gear fall, I left the bolts in.
Here are the new ARP drilled ring gear fasteners.
Torque to 67 ft-lbs with a good torque wrench.
ARP fasteners installed, ready to be safety wired.