Moving accounts from one hard drive to another

We had an issue on our server with an old hard drive, so we have had a new hard drive installed. We want to move the accounts from the old hard drive, which is now the secondary, to the new hard drive. Is there an easy way to do this?

I'm surprised it's not an option on the WHM control panel.

 

I tried that, but none of the accounts on the secondary drive are showing up.

 

I have it set up as hdc3.