Expand the Capacity of Diskstorage in Backup Exec 2014

Hi

I Created 100GB Diskbase storage of Backup Exec 2014. Now i feel that it is not enough disk capacity. I need to expand that disk capacity to 600 GB.  I brought new 500GB Hard disk and plug into that Backup exec media server. i need to expand that same disk storage (100GB to 600GB)(That 100 GB disk storage already have tha Backup Data)

Thank you