Ed,

sorry mate but I can't be precise as I just don't remember exactly what I done but I had the same scenario as you have.

Iirc you don't need the securiy code for the donor pump, I think I just went into immobikiser (may have been cim) and selected engine ecu installed or kfmay hqve been cim and engine ecu installed.

I just then entered the cars security code and followed any on screen prompts on tech 2.

You know when its done as the electronic warning light stops flashing.