There was a recall for my seagate HD. I let it expire because I did not want to part with my Imac and the drive was working fine. Three months after my free-replacement offer expired the drive died. A local authorized service center quoted me $450 for the replacement. I bought one from iFixit for $108 + shipping and installed it myself.
The guide was very helpful because it told me what to expect, what type of tools were needed and where all the cable connections were. The fix went flawlessly and Time Machine worked perfectly to restore my system.
The experience was good. I feel empowered that I am able to get into my Imac and replace things. It helps to take the time to be extra careful so as not to damage the tight-fitting cables and connectors.