SanDisk has released the DMG firmware images to allow SSD firmware update on MAC operating systems. Each capacity drive has a separate Firmware DMG. You MUST use the correct firmware DMG for the capacity SSD you have installed.
WARNING: Applying the wrong firmware DMG to your SSD product will render the drive unusable! Please confirm the capacity of your SSD product before proceeding with the firmware download and update.
Verify the capacity and model number and capacity of your Extreme II SSD and download the corresponding firmware DMG
The FW DMG file will need to be restored to a blank USB drive using disk utility. Once you have created the bootable USB drive you can boot into the FW upgrade utility to upgrade the FW of your SanDisk Extreme II SSD.