Download all files in your desired directory and unzip them all. All blend files are indexed in asset browser and all textures have relative paths so they are ready to drag and drop into your scene. Just download all zip files into your assets directory and unzip.

There should be 6 sub-directories:

and 7 files:

blender_assets.cats.txt

flat.blend
grooves_1.blend
grooves_2.blend
grooves_3.blend
grooves_4.blend
grooves_5.blend