MacBook Air up and running within 1 hour!!!
40 minutes - 1 hour
250 GB SSD crashed after upgrade to Yosemite. Using my limited diagnostic skills I found that the problem was related to an error with the partition map (it couldn't be read). I tried everything I could to format and partition with no luck.
I upgraded to a 500 GB SSD. It took 10 minutes to switch out the SSD. I used Carbon Copy to transfer the OS from an external HD to the new SSD, which took around 30 minutes. With the bigger HD space, I don't seem to be using as much of my memory (I use Memory Clean to track my memory) compared to the 250 GB SSD (when it was functional that is).
The screws on the bottom of the MacBook Air are very shallow. Be sure to apply enough pressure downward with the screwdriver when loosening/tightening to make sure you don't strip the screws.
T5 Torx Screwdriver
P5 Pentalobe Screwdriver Retina MacBook Pro and Air
MacBook Air 11" (2013-2015) 13" (2013-2017) MacBook Pro Retina 13" and 15" (2015) SSD