How to insert a Pre-Image script

Has anybody done a Pre-image script (like to change BIOS settings and Firmware updates) through the BigFix option? I looked at the screen offered in the Bare Metal Dashboard but it wants you to create a .rad file somehow (using RBagent).

OS Deployment covers this kind of scenarios leveraging on Scripting Toolkit Windows Edition (based on Windows PE) provided by the main hardware vendors like IBM, Dell, HP. You can create your own
custom hardware configuration installing on a dedicated machine the Scripting Toolkit suitable for your HW and then create a customized bootable Windows Preinstallation Environment (Windows PE).
The .rad file is the way OS Deployment packages the Scripting Toolkit to allow to be imported and then deployed on the targets that completed a PXE-boot. The target will load the Windows PE and then starts the execution of the hardware configuration as your prepared with Scripting Toolkit.

Where do i get the toolkits from each vendor?

Depending of the system you are dealing with.
I know with Lenovo you can run the BIOS update tool and then do that task.
or are you trying to change lets say UEFI to legacy to image or vise versa.