I got this from doing a little research so take this with a grain of salt but you might be able to update it via USB but this might only update phone and Bluetooth compatibilities not the full firmware

__________________
'04 4.4 X5 Toledo Blau Sport Pkg
'06 M5
'02 M3
'91 850I Manual Swap
'76 Porsche 911 3.0 Carrera Swap Project