You need :

The NavCoder program NavCoder Website

A Resler iBus interface IBUS Interface for BMW cars

A PC that you can connect to the Resler iBus interface, if your laptop does not have a serial port (9 pin D) then get the USB version of the interface.

You'll need to register NavCoder for any of the BlueTooth options.

Connect the Resler interface to the car, usually the easiest place is the CD Changer 3 pin connector, and PC.

Run NavCoder, select 'Code' then 'Telephone' then select 'BT Pairing'.