Please see this page (or the Author's Link above) for instructions. Nevertheless it is possible to modify an AMI Aptio type V BIOS by using CodeRush's UEFITtool, which is part of the UBU tool package.
To quote Fernando from the Win-RAID forum, 'Only the patched variant (see above) of the MMTool v5.2.0.24 is usable with many Aptio IV BIOSes (not all of them). MMTool Aptio MMTool Aptio MMTool Aptio MMTool Aptio Mod MMTool Aptio UEFI BIOS Updater v1.7x.x UEFITool0.22.4 AMI Flash FLASHEFI (P67/Z68) UEFI back to AWARD GB EfiFlash 0.52 Efiflash 0.62-mod Efiflash 0.65-mod Efiflash 0.74-mod Efiflash 0.80-mod Efiflash downgrade Phoenix Mod Tool 2.19 (SLIC) Mmtool 4.
That is why the UBO tool may not be able to update all BIOS modules of AMI Aptio V BIOSes (the tool will only show the version of the currently inserted BIOS modules). I actually used the patched which works for both Aptio IV and V (my board has Aptio IV and is older than his). Unfortunately, the currently available AMI Aptio V MMTool v5.0.0.7 has problems with the update of certain BIOS modules of the latest Intel chipset mainboards (X99 and newer). v5.0.0.7 (for the newest Aptio V BIOSes) and supports all Intel and AMD platform BIOSes.