There's some info in this thread:
https://x3.xbimmers.com/forums/showthread.php?t=1792056
Post 5 links to the needed MOST cable, and new plug for the 6WB. Do you have MOST cable going to your current cluster? If so, you'd just need the new plug (you'll pull the connectors (MOST and standard wiring) from the current plug and move them to the new plug). If you don't have the MOST connector back there, then you'll need to get the cable, and you'll run that wire and you'll put the new MOST wire and old standard wire connectors from your cluster to the new plug.