Changing Ignition barrel
 

Can anyone tell me what this entails? Is it a simple case of swapping barrels or is there any ecu work that needs to be done after?

just the mechanical part has no electronics.

Thanks for that! What do I do about the chip in the key?

as i said u are only replacing the mechanical part of the key cyl nothing has to be done but transferring over the tumblers from the old cyl to the new one.

It is easy to do.
I used a Dorman kit. It comes with instructions and a sheet of paper to keep track of the tumblers you take out of your old switch.

They put together a video:
Chrysler Ignition Lock Cylinder Key Matching - YouTube