Moving the FSMO roles with the AD PowerShell has the following advantages:
It must not first connect to the future Domain Controller role holders are made.
Only the Seizing (role holder is offline) the FSMO roles will require an additional parameter, you must use -Force parameter.
Transferring or Seizing the FSMO roles must not necessarily the role holder or the future role holder be conducted. You can run AD-Powershell command from Windows 7 Client or Windows Server 2008 R2 memeber Server (after RSAT installed).
The FSMO roles are moved using the Move-ADDirectoryServerOperationMasterRole to another Domain Controller.