2009 27" IMac I7 first gen quadcore
1 - 2 horas
The computer was starting to show its age, kind of slow by todays standards, with Mountain Lion (10.8.2) it took a long time on startups. A speed boost was needed.
The upgrade-repair went excellent thanks to ifixit's guide, very complete and spot on. It took me about an hour but I took my time. I vacumed afew years of dust out of it. I installed a Samsung 840 500GB SSD it startsup in 17 seconds now !!
Just follow the excellent guide carefully and you will have an easy time. Sorry no pics, I just tore into it.