Would you mind elaborating on how it is used? I'm guessing the drilling part is done by hand? Did it take very long? Thanks.
Sorry in advance for the novel. I hope my description can paint you a good mental picture...
The kit comes with a hollow guide bolt that the long drill bit fits in. That guide bolt gets threaded into the carrier above the broken bolt (the shaft locking bolts usually don't break off flush at the head, they generally break down a couple threads into the carrier because of how/where they are stressed).
With the hollow guide bolt installed in the carrier as far as possible, the carrier needs to be rotated so that the threaded hole is sticking out past the differential cover surface of the housing. Then drill out the center of the broke bolt. The long bit that comes with the kit is necessary to get the appropriate reach past the differential cover surface of the housing (the hole is drilled with the bit running parallel to the axle tubes).
The drilling was done with an electric drill. This was simple because the hollow guide bolt puts the hole exactly where it needs to be. This drilling operation could never be done freehand IMO (it'd walk off center and/or ruin the threads in the carrier). My only caution would be to pay attention to the hole depth relative to how much bolt you have left in your carrier.
Then comes the easy out that's included with the kit. This part was done by hand, by my buddy, and is certainly the more challenging part of the process. He's got an appropriate touch with a hammer to get the easy out to bite, and then the screw was removed by hand (or maybe with a small plyers or ratchet).
With his help, rolling around on my garage floor, we had the broke bolt out in less than half an hour. The truck was already on jack stands with the differential cover off. If everything goes perfect, the process should take minutes. Then, he showed me how to use the axles to pop the rear tube seals out. He's a great friend to have.
The same friend removed a different broken carrier pin bolt out of my Monte Carlo's carrier about a decade earlier. He was able to get that one out with a pick set though as it wasn't stuck, just broken.
I hope this helps you, Rob. It's certainly the "right" way of going about this repair.