Why don't someone get a wiring harness from an earlier vehicle and see if it works? I don't know if/when they changed the radios. Is that radio installed in an older Jeep or another Jeep? Chances are, the harness has not changed.
anyway, going to WalMart and picking up one just to see if it would fit would be easy and it can be taken back so no money lost there, only time. Of course you would have to remove the old radio but you are doing that anyway so.....
I would never cut wires and hardwire unless I had to, especially for older vehicles that a wiring harness is cheaply available for.
The link above is very expensive, so theres more to it than first glance.