Installation:

Unpack 100 Sci-Fi Round Emissive.rar and copy both folders to C:\Users\YourUsername\AppData\Roaming\Blender Foundation\Blender\BlenderVersion\scripts\addons\DECALmachine\assets\Decals

For better management when using DECALmachine I split pack into to two different folders but if you want to have all decals in one folder you can marge both folders together by just copying folders from one to another.