Well it depends on what OS is on the Roamio currently. If it is TE4 then the Roamio should format the 10TB itself. If on TE3 there will be a process. For me, it's worth the "process" to stay on TE3, I way prefer it to TE4. Others will disagree. The process is not that tough. Maybe boot it up with current drive to see what OS it is on, look at the system screen and check the OS version, maybe post here. Does the Pro have lifetime service or is it monthly/yearly, just curious.totally new to the tivo world.... having just gotten a refurb roamio pro that has not been turned on (by me), will switching out the 3 TB drive for a 10 TB drive first work without having to worry about all the things mentioned in the parts of the thread that i have scanned thru as it seems everyone had an existing unit that had been setup and with recordings they wanted to keep rather then start out with a new drive?