I added an OWC 120Gb 6G SSD to the stock terabyte on my i7 2.3 mini. Not really broken in to anything harder than an old G5 before, other than adding RAM to MBPs.
I had to take it slowly and carefully and did have to backtrack a couple of steps when reassembling to get the new SSD to seat properly but all went smoothly, nothing broke, and I now have a quad core i7 with 16Gb of RAM, a fast SSD for the system and a slower but large data drive. Which is nice.