30 Minuten - 2 Stunden
My hard drive was beginning to fail.
The exchange went well. I already had experience digging around in the machine when I upgraded the RAM. I did have to take it apart a time or two to get everything working again. The connections for bluetooth and WIFI are pretty delicate and can come unplugged easily.
Dont forget to re-attach the heat sensor for the mac mini (that little wire with the little microchip on the end). If you forget, your mac mini 2009 model's fan will run at 5800 rpms to remind you that you missed something.