Hello all and wondering if someone can help me.

I have a 2010 l322 with a battery drain from a bum bcm, got a second hand one from a scrap yard and changed it over but of course the keys no longer work. So I am wondering how to reprogram the bcm to the car and get the keys working again. I have the v160 jar sdd and through this site learned how to get into engineering mode from opening software update html file that bypasses the need to provide a password. I’m wondering what to do next as I don’t know how to get the key working again. Accessing the bcm module just says it reported the wrong vin. Please could someone give me some tips as I can’t afford to pay some guy 300 quid to fix it. Many thanks, Charles