The download contains 4 files.
1 - The Actual prefabs [StoneGlassBox_prefab.vmf, StonePillar_prefab.vmf, StonePillarFire_prefab.vmf]
Which goes in:
C:\Program Files (x86)\Steam\steamapps\common\Counter-Strike Global Offensive\bin\prefabs
2 - The Scene [StoneLight_Scene.vmf]
You won't be able to see the flying mushroom, as it's a custom model from somewhere.
Some of the textures will not be available when you add this prefab [Custom textures].
If you use this, a little credit would always be appreciated.