My first semester in an IT college course made me realize that owning a laptop would be invaluable. My girlfriend had an old early 2011 Unibody, but the upper case was chewed, a few of the keys were popping off, and some had been replaced with random spare keys. Due to this state, she couldn't sell it, so she decided to give it to me for free. The end of my first year, I ran into a problem with the number keys not working at all. Decided that for the price of a very cheap laptop, the repair parts would be cheaper. I could replace the upper case, battery, and put some feet on the bottom which had also been lost—giving my laptop a chance for a new life.
The repair went amazingly!! The parts arrived quickly which I had to fetch from over the border to avoid extra shipping fees (which every Canadian will know about). The guide was super handy, every step was well documented and thought out. The repair did take longer, as I did install case feet and a new battery, but I would say 3 hours was very accurate for just the case. I wouldn't even call the repair difficult—the guide really did make it super easy. The repair was successful, and now I can write Bash shell scripts in VIM to my heart's content.
Go slow, and read the guide VERY carefully. I was a little sleepy, and I had a time crunch, as later in the day was a family get-together. I made a mistake with the speaker connector and pulled horizontally instead of vertically, and ended up de-pinning one of the speaker wires (seems like it was one of the sub-woofers as I still have some sound)? I don't actually care about this very much, but I did see you can buy a replacement for around 15 USD. I might leave it for the time being, as I always use headphones. Also BUY THE PRO TECH TOOLKIT—the kit was VERY helpful, the construction, quality, and just the thought that went into designing that kit is A+++.