How to expand logical volume in HP ML150 gen 9 , smart hba h240

I have replaced two hotplug 600gb sas drives from 300gb sas drive (raid 1) . The smart storage administrator have no option of increasing the logical volume to the new drives. So now i’m stuck with 300gb-usable in a 600GB drive. How do I increase the logical volume to 600GB ? with out loosing data ? pls help screen shot of ssa