A few comments having updated 5 machines in a row:

1) The OWC 2.5-3.5” tray / SDD holder is a better option than the ICY dock used here. The OWC tray is made of die-cast metal and allows much better air circulation than the plastic icydock. Plus, the temperature sensor board (sourced from OWC) has more room between it and the iMAC display panel

2) Carbon Copy Cloner and a external drive enclosure or dock with a FireWire 800 interface are your best bet re: a fast and easy transfer. Apple Disk Utility will not clone a drive you’re booting off so unless you’re willing to wait through an endless boot from a DVD install disk, get Carbon Copy Cloner. It will even re-size / partition / install the recovery disk.

3) It’s a shame that in some cases parts-only kits are not available here or elsewhere. I only needed a single set of tools.

4) By far the longest-taking aspect of the upgrade is the hard drive transfer. If you have multiple machines that need a upgrade, bring multiple docks and start cloning in advance.