The 1TB hard drive crashed and I reformatted and restored it but then it crashed again about a day or two later.
The hard drive replacement was a breeze. It took about 1hour and after formatting the new drive and loading OS X Yosemite all I had to do was restore my files from my backup USB drive. The free hard drive replacement guide was easy to follow. Also it was a nice upgrade from my original 1TB drive to a 2TB. Over all I am extremely satisfied with how everything went.
The only issue I encountered was after I completed the install my drive fan was running at max speed. Got on the web and found an app called iStat Menus. This app had a menu that enabled me to control the fan speed with no problem.
2 TB 3.5" Hard Drive
Heavy-Duty Suction Cups (Pair)
TR8 Torx Security Screwdriver
TR10 Torx Security Screwdriver