My Daughters Macbook Pro
20 minutes - 1 heure
The battery swelled/exploded and destroyed the trackpad - I had to replace the battery and the trackpad.
Simple. It took less than 30 minutes once I had all the parts.
A few of the screws on the frame are extra long. I marked them on the back of the case - it was a lifesaver since it was several weeks after I took it apart before I could put it back together.