MSA1050 - Delete Disk Group

Hi,

I have a MSA 1050 with VE100R002 firmware configured as below:
- Pool A -> DiskGroup1 -> 4 x 300GB 10K SAS RAID5
- Pool A -> DiskGroup2 -> 3 x 300GB 10K SAS RAID5
- Global Spare -> 1 x 300GB 10K SAS

There are 4 LUNs exposed to the hosts.

I want to make a backup of the data and delete 3 LUNs, coming to occupy only 500GB. At this point, could I delete the DiskGroup2?
Do I risk losing the data on the remaining 500GB?
I would like to delete DiskGroup2 in order to recreate a new Virtual Disk Group with 9 disks in RAID5.

Thank you a lot
Paolo