Need help expanding HD space on Smart Array P410i (replacing two drives)

I have 2 x 2TB SATA drives I need to install on RAID 6 array. These two drives will need to replace two of the current drives as there are no more free bays. I need someone to direct me through the whole process. More Information - Smart Array P410i in Embedded Slot Internal Controller Controller Status OK Controller Smart Array P410i Slot 0 Controller Serial Number 50014380165F2BB0 Bus Interface PCI Hardware Revision C Firmware Version 5.14 RAID 6 (ADG) Status Disabled Rebuild Priority High Transformation Priority Medium Surface Scan Analysis Priority Idle Surface Scan Delay 15 sec RAID 6/60 Alternate Inconsistency Repair Policy Disabled RAID 5/6/50/60 Degraded Mode Performance Optimization Disabled Physical Drive Request Elevator Sort Enabled Monitor and Performance Analysis Delay 60 min Maximum Drive Request Queue Depth Automatic Number of Ports 2 (Internal only) Number of Arrays 2 Number of Logical Drives 2 Number of Physical Drives 8 Array Accelerator Array Accelerator Present Yes Cache Status OK Array Accelerator (Cache) Ratio 25% Read / 75% Write Total Cache Size 1024 MB Cache Backup Power Source Capacitor Battery/Capacitor Pack Count 1 Battery/Capacitor Status OK Arrays SAS Array A - 1 Logical Drive(s) SAS Array B - 1 Logical Drive(s) Logical Drive(s) / Local OS Access Name Logical Drive 1 (1.6 TB, RAID 5) \\.\PhysicalDrive0 Logical Drive 2 (1.6 TB, RAID 5) \\.\PhysicalDrive1 Assigned Drives 600 GB 2-Port SAS Drive at Port 1I : Box 1 : Bay 1 600 GB 2-Port SAS Drive at Port 1I : Box 1 : Bay 2 600 GB 2-Port SAS Drive at Port 1I : Box 1 : Bay 3 600 GB 2-Port SAS Drive at Port 1I : Box 1 : Bay 4 600 GB 2-Port SAS Drive at Port 2I : Box 1 : Bay 5 600 GB 2-Port SAS Drive at Port 2I : Box 1 : Bay 6 600 GB 2-Port SAS Drive at Port 2I : Box 1 : Bay 7 600 GB 2-Port SAS Drive at Port 2I : Box 1 : Bay 8 Unassigned Drives None Spare Drives None