In preparation for the upgrade from Snow Leopard to Mavericks, I finally decided to replace the original internal Apple Disk Drive with a fresh one from you folks. While the old drive was still operating fine, I knew it was on "borrowed time" as the iMac is 6 years old.
Both your written instructions online and the Video were EXCELLENT! It does get a bit scary to open up your iMac for the first time since leaving the Apple factory in 2007, but it all went perfectly. Thanks.
Keep up the good work iFixIt!