If you haven't installed BMS yet you can find all of the details and files you need here
It is critical that the MP SOPs are very closely followed or the experience can be ruined for everyone. You can find details of the 185th MP SOP here.
Once again the mission will require a ramp start. There are some startup differences between BMS and AF so members are strongly advised to practice this beforehand. You can find links to BMS ramp start check lists and other other useful info here.