How do I upgrade drives on my My Book Duo?

I have a a 6TB My Book Duo that I have set up with RAID 1, which leaves me 3TB of available storage. I am trying to figure out how I would be able to upgrade my drives without losing any data. My understanding is that the RAID 1 setting mirrors the drives together so that if one goes down the other is just fine. If I want to upgrade the drives to a larger size, do I simply do it one at a time. For example, would I remove and upgrade the 1st 3TB drive to a 6TB drive and allow it to mirror the content from the other drive, and then do the same for the 2nd drive?

Hi there and welcome to the WD community.

I have not tried this, however i would recommend backing up the unit before trying this but, lets see if another user can share some information or tips on this matter.

I know this is an old post, but I upgraded my MBLD 6TB (2x3TB) device to a 12TB (2x6TB). See [GUIDE] Debrick a MyBookLive DUO - #285 by BobCat124