I suspect my radio amp is shot. Head unit responds, just no sound on any setting. Is this a simple swap or does a different amp now need to be flashed by the dealer or something?

 

Plug and play.

There are 2 kinds, best to remove yours first to match numbers.

 

^ What he said. I did some amp work and all it well. No reprogramming needed but you *may* want to swap with the battery disconnected to be safe. Also when removing the amp, careful not to unplug the seatbelt sensor (two wires) and power the vehicle up. If you do you will get a permanent SRS fault which you need an LR centric tool to clear (GAP tool, etc).