WD EX2 Ultra Expand Storage

I have added two 3TB HDD to my EX2 which has 2 HDD in raid 1 configuretion Can I use these two discs to expand my EX2 storage capicity and if so how do I do it Cheers
PS I can see in WD dashboard and Windows explorer


Please use the instruction listed below to replace drives in a My Cloud with a higher capacity drive:

Note: This process is for a 2 Bay My Cloud device with RAID 1.