Good tutorial for Arkham mods?

https://youtu.be/P4yq_ovokrE?si=T2Xmn0Ztg7tZ_DiU

I was trying to install a HD texture pack into the Steam version of Origins to improve the graphics, and get my feet wet. Unfortunately, none of the tutorials I've found have quite lined up with my computer, partly because I'm storing games on an external SSD.

Is there a "go-to" source for this, or another type of mod you'd recommend starting with?

Any tutorials or guides you can recommend to get started would be appreciated.