There is a teeny weeny hurdle you could run into during this process. Particularly when you are creating a DRS backup device to take the newly upgrade image back to the production environment.
If you are doing something like what I describe above and are seeing an error message on the DRS Backup Device page that says something like <spicolivoice> "Duuude, I'd like to help ya out brah but the Local Agent has bailed on us...." </spicolivoice> then I may have the fix you need.