I'm not 100% sure, haven't done it myself, but here is what I'd try:
* Bring the system completely offline and save the model, detach the databases.
* Make a backup of the system model (usually in the VU named like the node in a folder named "etc").
* Copy all the database and the DB log files to the new server (and re-attach the files in the old instance).
* Attach the databases to the new instance and bring them online.
* Set the new addresses for the DB-s in the IA and engage the "upgrade software" feature.
* Set the new addresses for the DB-s in the system's VU's and synchronize the changes.
* Go over all the relevant settings in the DB-s themselves.
* Bring BCM VU-s online and see if the system works.
If you need to restore the system to the previous state, just make the system use the old model file.
Best wishes,
Jaanus