How do I change a ignition cylinder in a 2005 530i

Purchase the new lock and cylinder with keys, also you need to purchase the '05 remote style key too. Have good selection of tools.. you will need to remove the cylinder tumblers for the old key. Unless your having the The dealer program the new RFID keys in the computer. Most dealers fee is $200 BMW, $300? The German brands use proprietary technology. They all do! wait... I think this is beyond the average owners skill set.. I suggest you have this done inquire first, but total, approx $500-$600