[Kenny]

There is a mod similar to what you are trying.

The mod is conversion of a EU Fxx 523i to a 528i. It is valid for cars of production period where both models were delivered with the same N53 motor, albeit the 523i being detuned in HP & Torque.

But the DME Hardware numbers was identical, just one is detuned.

Reading the info on it, they modify production dates and FA etc. (7 page instructions).
If you do try, its always safer to make backup of ecu before trying.

Good luck