I would like to mod the bios for an Asus U24E notebook, in order to have it boot in pure UEFI/GOP mode and ideally with Secure Boot (Microsoft public key). Since the BIOS (as obtained from the official site) is only 2MB in size, I figure I may have to actually remove the CSM and legacy OpROMS to do so.

As far as I can tell, the BIOS in question is already UEFI (AMI APTIO IV based, I can see several PEI and DXE entries when opening with MMTool) but it does not include a GOP driver for the Sandy Bridge GPU or a way to turn CSM off in the BIOS GUI (even as a hidden entry when opening in AMIBCP).

Is doing this possible at all? What would I need to do?

For reference, attaching BIOS in question