There was a recall on the rear pinion but where it would back off and the fastener they put around it is suppose to have a Allen key bolt on it but mine doesn’t it’s like a socket. Any idea of where to get one of those sockets or how to get that one off and replace it?

 

A regular socket will fit those bolts. I recommend using a six point socket to remove them.
If there is a recall, wouldn't the dealer fix that for you?
Anyway, I recommend you get instructions for complete differential gear replacement, and just skip ahead to the pinion nut section.
For the nut in the picture, take a look at part number USA33253. It's by USA Standard Gear and they publish instructions and have a tech support line 866-748-0902. You may not want to go with USASG, I'm just giving you a starting point.

 

That piece you are seeing with the Allen screws are part of the pinion recall. The nut takes a 1 1/4 socket. As part as the recall, The tech is to use a torque wrench and check the nut at 50 foot pounds and then 100 foot pounds. If the toque check pass then the this retainer is installed so the nut would not back off.