Old HDD (256GB) seemed to be failing, and was reaching capacity, wanted faster SSD and more storage (512), was also replacing battery and upgrading RAM (4 GB to 8 GB)
With the proper tools from ifixit and great instructions with pictures and video the repair went fine. The most difficult part is getting the info from the old HDD onto the new SSD so that it boots right away without a hitch. I used SuperDuper! to clone the old drive and ran into one error, either a small portion of the old drive was bad or perhaps one file was corrupted. SuperDuper! provided immediate support that worked (even though I had not registered).
I would feature this file more prominently: https://www.ifixit.com/Misc/HD_Software_...