It seems that there is a little debate over the reliability of the pumpless mod. Here is what I do with at least 5 pumpless bikes under my belt without issue...
Purchase Grizzly Needle Valve and replace the stock one with it
Remove the carb
Set float level to 2004 and up specs
Either trim the "on" tube from the petcock, keep the petcock on reserve, or buy a Pingel High Flow valve. If keeping the stock valve make sure it flows well. Remove it, whether you are modifying it or not, and check the screen/filter to make sure it is clean and clear. It's a good time to pick up a rebuild kit and replace the gaskets and o-ring.
Run 5/16" fuel line from the petcock to the carb going over the top of the intake. An inline filter is optional and if you choose to use one make sure it is a high flow (I have had good luck with Russel brand filters - plus they are serviceable). If there is doubt about the filter just don't use one. Make sure the fuel line doesn't have a lot of slack in it - you want the straightest line to the carb as possible.
Vent the gas cap AND make sure the vent line going to the tank is clear (both going into the tank and the rubber line that goes to the roll over valve). I blow compressed air in both directions just to be certain.
Make sure the roll over valve is functioning properly or just get rid of it - Personally I just remove it.
IMO - most people get into trouble with the tank not venting properly so the last 2 steps are just as important as the rest of them.
Please treat each step as important as the next. All too many times when people have issues they, for some reason, have skipped a step somewhere.