Is it possible to migrate data from one existing raid 0 array to a new raid array using b320i

[hesral]

I am managing a HP proliant server with a dynamic smart array b320i raid controller. The server is running windows server 2012, and has hp smart storage administrator installed.
I have one raid 0 array of 3 physical 1TB disks, creating one 3TB logical disk.
I have one 3TB physical disk connected, currently configured as one array.
I want to migrate the data and usage from the existing 3TB raid array, to the one 3TB physical disk, with as little downtime as possible. I need the 1TB disks for other things.

I was thinking of doing the following:
1) Set up the 3TB disk to mirror the raid 0 array. Bandwidth is no problem. The reading and writing is well below what the one disk will be able to deal with. The old 3 disk setup was for size, not speed.
2) Wait for the cloning/mirroring to finish.
3) Remove the 3 1TB disks, leaving the 3TB disk as the physical disk for the old 3TB logical disk.

Will this work?
Will this be possible without any more downtime than the time it takes to shut down and remove the 1TB disks?
Does anyone have any experience with this kind of operation.
Does anybody know of any step by step guides for this?

I have other options, but they involve shutting down the service that produces the data, and serves the data to clients, for several hours. That is painful, and I hope to avoid it.

Thank you for your attention.