5 - 30 minutos
I needed to upgrade because of the amount of space I needed for video processing and storage.
As far as replacing the drive and memory it was a breeze, the only problem was Microsoft Office.
I am running Lion and office 2011 so I don't know about other versions, when you clone the drive to the new drive, the license for office doesn't initialize properly. In order to have office function you need to have a "Product Key". Since mine was an upgrade from 2007, I didn't have a 2011 key, and subsequently I had to buy a replacement disk from Microsoft for $29.95.