Yep, those are the basic steps. I would also recommend saving a screen shot of your working config before you make any changes and probably backing up your flash drive (always a good idea) before doing anything, just in case. Have you precleared the new drive? This isn't needed from a formatting standpoint, since it will be the parity drive, but it's a good stress test on a new drive. Also, you are right about #6, when you restart things, unraid will need to rebuild parity onto the new drive.