Steps to install:
Download ZIP file.
Navigate to Documents/My Games/Starfield/
Extract to that directory or open the ZIP and drop the data folder there and it'll do the rest.
Make sure to have a StarfieldCustom.ini file created in your Documents/My Games/Starfield/ folder
In that file you need to have this added
[Archive]
bInvalidateOlderFiles=1
sResourceDataDirsFinal=