urd maf sensor calibrator?

im looking at getting one of the maf calibrators, does anyone know how to alter the stock map that comes with the device or how does this thing work

 

You should have received software from URD that you will need to install on a laptop. You then need to buy a USB to 9-pin cable to hook up to the URD unit (you have to take the cover off to expose the port). Once hooked up you can then tune the calibrator. To do it right, you will also need to install a fuel/air mixture gauge to make sure you have the correct ratio.

There is a thread over on TN, where guys have uploaded maps, may be easier to find a map that matches your setup and just download.