EX4100 How to downgrade from RAID1 to JBOD

Hello everybody, I have EX4100 with two 4TB disks in RAID1 mode. I want to change my RAID1 configuration to JBOD without formating both disks. I figured out that I should downgrade rather than switching to JBOD in order to avoid formating of both my drives and losing my data but I CANT find how to downgrade. Please help me.

See the dedicated subforum for the EX Series where users more familiar with the EX4100 may be able to assist. This subforum (My Cloud) generally discusses the single bay/single drive My Cloud.