Don't forget to get your Toyota red coolant and a few gallons of distilled water ahead of time as well. In my experience getting the red coolant from Toyota is hit and miss. I actually get mine from the nearby Lexus dealer instead since the Toyota doesn't carry it.
I just got done doing mine just a week ago. It's very difficult to accidentally move the crank pulley. The cam pulleys definitely have more play as it were, which makes it easier to use those to get the belt back on. But if it's that much of a concern, then take some tape, put a piece on the...