I had to replace my MacBook Pro (Early 2011 Model)'s HDD after a total failure. I chose to replace it with a 1TB Hybrid SSD.
It was the first time I had ever taken my MacBook Pro apart. The toolkit that came with my HDD was very useful and had everything I needed and more to do the job! It was a simple process, however the HDD I received wasn't ready to use. It needed to be formatted to begin with (which I didn't know... and I wondered why the MacBook wasn't recognising the disk. After figuring that out, the replacement wasn't as bad as I thought it would be and now it is working faster than ever before!
As I didn't have any other computer available to me, I had to access the HDD through disk utility in Internet Recovery mode. I then restarted the MacBook and installed from the disk that originally came with my MacBook Pro. From there I updated it straight to Yosemite. The whole process took 5 or so hours due to the confusion with setting up the HDD. Maybe include this in the guide? I have never done a repair before so wasn't clued up on the ins and outs of the process.