Dell Optiplex 960 BIOS?

After some research about ME firmware (thanks to Plutomaniac), now I’d like to try to update the AHCI (or RAID AHCI) module inside the BIOS but it’s not as easy as I thought.
Managed to extract the ROM from the .exe file but I cannot find any useable tool to see what is inside.
could anybody be of some help? I installed the “classical” RST driver and use is with an SSD in AHCI (no RAID).

From that .exe you can extract both rom and hdr file using /saveromfile or /savehdrfile commands. However, the easiest way to mod is via PhoenixTool. Input the exe and it will recreate the exe with the modifications. I don’t think this forum has a PhoenixTool guide but it’s not difficult. Spend some time with it and you will figure it out. For example, module 20_21 has the RST you are looking for: