I would recomend a new install on a new server so you can migrate and you still have a working SIM during migration.
first do an export on the old server, commandline mxnode -ln > c:\export.txt.
install your new server set the general credentials for login on the destination servers.
Now copy paste the list from the text file you created. If you can use the logon credentials you can set trusts, snmp and wbem settings with the repair option.
if you have a small enviroment you can consider a virtual server for SIM.