If you don't want to buy a specialized pre heater, an electric skillet works great. Something that can get up to 400F. Make sure it's not placed directly on it, prop it up on some screws or what ever you deem suitable. It may not be necessary but it has given me nothing but 100% success putting chips on. Good luck bud, and remember the flux.
You want to preheat the board to prevent flexing cracking large temp differences that break things. Warping or breaking your board would probably ruin your day.
I love the skillet bit. What I use is an aoyue 853a
http://www.ebay.com/itm/Aoyue-853A-Quartz-Preheating-Station-/110803086034?pt=LH_DefaultDomain_0&hash=item19cc60ead2The reason I use it is more because it heats up the incredible amount of ground plane in these boards. Also activates the flux. With pre-heat, the amount of time on the chips is a lot less. Skillet would be better, 5-10 minutes at 360-370 waiting till the flux just starts to set is it. Then use the air low pressure (just enough to heat under the nozzle) and go 60 seconds.
Don't forget to get the chip right on the balls, I use a 6x loupe to watch as I move it into place.
C