Just finished jetting my 06 Honda 450R so i figured i'd post some instructions and picutures of changing the needle. Changing the needle is a little more involved than changing the main jet.
To get to the top of the carb, you'll have to take off the tank and plastic. You may want to loosed the two clamp screws on both sides of the carb so you can rotate it little bit. Once you have access to the carb, you'll need a 3mm allen to remove the two screws as shown