Installation :

• Unzip the "VGH - Ver.2.0.zip"
  
• Put the 3 folders (Vents - Grids - Holes) into a chosen directory (either the Decal Machine's default, which is NOT recommended, preferably in your own asset folder).
  
• Open Blender and hit F4 and go to preferences.
  Then go to Add-ons → DECALmachine → General → Assets → Import Existing → Library from Folder or .zip
  
• Select one folder at a time.
  
  Decal Machine will then install the selected zip file, and it will be ready to use.

! Updating the Asset Library for Blender 4.2x and above !

In order for the decals to show in your D menu, you will have to update them.

It's very easy, just follow the steps from Machin3's update video here :