Given a 5400RPM drive for the entry level MacMni2011 is very limiting. I've already upgraded my RAM into it's maximum 16GB. I can still feed the need for speed. One last thing to do is transfer my Phoenix Evo 115GB SSD from my 13" MBP to the Mini.
Comparing the old drive and the SSD there's a big gap in drive space. So I need make the SSD and the old HDD sit together in one box.
After acquiring the Mac Mini Dual Hard Drive Kit, I quickly disassemble my Mac Mini. You can never go wrong with the included tools, specially the logic board remover. It's a time saver, and it makes your DIY much more faster.
DIY - it's best when you have the right tools to do it. So I highly recommend getting the Dual Hard Drive kit, not only for your Mac Mini.