2 - 4 horas
I wanted a ssd in my new Mac mini especially once thunderbolt takes off. I didn't realize how complicated the installation was until seeing the I fixit guide. After a bad MacBook pro optical bay replacement i knew I couldn't wing this one.
It went well but took even longer than i expected to complete due to the torturous process of reattaching the cables. I should have taken pictures but it was stressful. If it wasn't for not only the guide which I had prominently displayed on an iPad the whole time, and the kit which I am so thankful I bought, I would have messed this up.
Take pictures. Also don't drink so much coffee your hand shakes at the end when you tor reattach the tiny cables. Last, allocate at least 3 hours to be safe.