Download and place it in the subfolder gfx/terobjs/ of the custom resources folder used by your client.
Since cupboard's resource file depends on some other resources, and client requires for them to be in the same location, download following files too and place them in the corresponding folders:
- http://game.havenandhearth.com/hres/gfx/terobjs/crate.res to gfx/terobjs/
- http://game.havenandhearth.com/hres/sfx/clonk.res to sfx/
- http://game.havenandhearth.com/hres/sfx/creakdoor.res to sfx/
That's how it looks in-game:
Enjoy!
EDIT. Removed minimized towers and updated download URL.