I've never been able to comprehend this nutty "it's old, so let's destroy it" mentality. This hardly differs from buying a new iPhone and spraying it orange, only to put a funny face on the screen for a silly holiday.

The concept isn't all bad, however. But don't be an idiot and harm a good working Mac in the process. Follow the steps, but instead of paint, use your common horse sense and put a bright orange cloth around the Mac, making sure you can still see the screen. Then make whatever funny faces you like and have those graphics fill the screen. Makes for a fun holiday without epoxy or paint (i.e., you're Macs integrity is retained).