Mac Pro trash icon in dock!

Hey guys, I came across a really cool post that details how somebody was able to get a Mac Pro icon for their trash can in the OS X dock.

Here's a picture of how it looks:

Empty:

Full:

The details on how to get it are on the post in 9to5Mac that I've linked to. If you need any help just comment here and I'll run you through the steps, but I doubt you'll need it, it's very easy.