I just wanted to give another option to this thread:
Technically, once you run out of mileage, ECU is locked and you have to get a new ECU. Instead of spending thousands to get a new ECU, some tuners might be able to help. For example DUDMD (no relations) offers a service for M57 (however, i think they might be able to do it for N57 too) to reset the ECU remotely.
https://www.dudmd.com/products/2009-...et-programming
Any competent tuner should be able to get it done, as they should be able to "rewrite" your ecu. Depending on the age of your car, some tuners might require you to mail them your ECU so they can do a bench unlock and reset.