Our front-end developer is constantly opening and closing various VM's and PSD's, so he needed a faster hard drive. None of us had played with an SSD yet, so it was the perfect excuse to get one and perform open heart surgery on the Mac Mini.
Easy and simple. No drama at all thanks to the iFixit guide.
The lower/main drive in these mounts to the wifi antenna shield, which is one of the last things you reinstall. Be careful as the floppy drive (har dee har har) can unplug itself from the logic board rather easily.