It's relatively easy, honestly i just did the same as with my main PC.
I recommend you use Win 11 (LTSC) / Win 10 Enterprise LTSC as it's a bloatware-free official OS edition from windows and not some edgy teenager that wants to be popular by making slightly adjusted ISO's. PLEASE try looking at what these LTSC editions are.. it might save your *** if you go deeper into DMA.
Download a multi-tool such as the one on shillette (dot) com (IN THEIR DISCORD, OR ON MAVISDMA)
It should give you a list of the drivers you need to download or it'll just download them by itself.
After that's done go into Windows Defender and now disable Memory Integrity, Controlled folder access, and all the stuff in exploit protection.
Then hold down shift on your keyboard and restart your PC.
It should put you into the troubleshoot screen, go into advanced and into the "Edit UEFI" button.
Once you are in BIOS, disable Secure-Boot (Sometimes you don't have to, it purely depends on your firmware.) VT-d / IOMMU (VT-d on Intel and IOMMU on AMD, but this also depends. If you are to play Valorant then you NEED to have VGK firmware and contact your seller about the IOMMU and BIOS stuff) For the BIOS, that should be all.
Soo.. yeah.
That's how i setup my laptop.
Cheers!