I haven't been here much since christmas, sorry.
It's a little bit fiddly, but it can be done.
The easy part is to find a VCMII or a Nano VXDiag tool on ebay or VXDiag.net - they are chinese clone hardware diagnostic tools that can be connected via USB to a Windows computer. They will usually ship with a bootleg copy of a piece of software from Motorcraft called 'IDS' - which is the same software that is at all of the Ford dealerships. If you get the software up and running with the tool, then you are good to go.
FORScan is a piece of software written to copy much of what IDS does, but it can do it with a cheaper ELM327 tool, although it can still work in with the VCMII or Nano VCX using what's called a 'J2534 Passthrough' mode. It's just that the ELM327 tool is not as fast and may not support programming modes for the
ECU - which requires voltage to be applied on one of the pins of the OBD2 DLC connector.
But from there it can get a bit tricky, because the dealers usually get a lot of training, and you'd have to figure out how to do the actual module install steps yourself. You usually have to select a 'Module Install' setop from the iDS Module Programming menu, that shares the VIN between all modules and sets up the
PCM with a bunch of information it needs. Then you have to run a PATS to get the keys and fobs all programmed in to allow the keys to start the car. The radio may need to be unlocked as well.
I've done all this on a BA Falcon, but not on a WQ Fiesta - but the technique should be roughly the same.
Luke