Great guide. When I saw how simple these instructions looked, I made up my mind: instead of leaving my MacBook Pro for a week at the local Apple Service Provider (why should they have to keep it so long?), I would change the battery myself at about a third of the cost. Working slowly and carefully, the whole thing took less than 10 minutes.
I would add just one thing: those 3 mm Phillips screws are really, really tiny. Do be careful where you put them down!