[RMS-Chef]

The key is to inform the community well in advance that you are moving and let them know that they will need to locally backup any PMs they may want and that they will have to register at the new board. You will be down most of a full day though. If I remember correctly you install the new board first and you can prep it as much as possible as users are not imported. We "pre-registered" all the board staff at the new board then did the account merge for them after the import before opening back up. You can merge users at any time after the import. Keep in mind that if you do some work getting that set up, backup your database before the import so you can restore it with all your work intact should there be an issue with the import and you have to start over.