URI/RIM connection to a Kenwood TKR820

Hi!!, recently purchased a Kenwood TKR820 repeater for a friend who is very interested in setting it up for GMRS, I was wondering if anyone has ever done a hookup like this and also any information on setting up a Raspberry pie to all of this to connect to their link.
Any help would be greatly appreciated.

For GMRS the Pi set up is the same as for hams except it must not register with the ham radio only AllStarLink network.

Grab the software from the downloads area of wiki.allstarlink.org. You’ll need a radio interface such as a Micro-Node AllStar RTCM or RA Radio Adapter Index Page