Its actually pretty simple to do
Setup as you normally would with a setup disc (All processing modes witched off etc)
Then use the sensor to calibrate greyscale (One click, to start, then cycle through the greyscale images when it asks)
Then use the tvs ISF menu to change the settings until you get as close to 2.2 gamma and a true greyscale as you can (If the tv has the setting, you may also be able to set the intensity)
Usually I set around 80% grey first using RGB HIGH then around 30% RGB LOW (The high changes the most, which also effects the LOW) .Then check greyscale again and continue until you get it as good as you can.
This assume you only have HIGH and LOW settings. Your tv may have full ISF control on every gradient In which case start on 80%
Then try and get all the ones done 50% and over, then onto the 0-40% ones
If the tvs a plasma, warm it up for at least a couple of hours first as plasmas drift all over the place with heat. LCDs need to be on half hour or so. (Also have the dvd player in use that your going to use to warm that up)
Plasmas tend to change over time, my sony tv has been pretty much rock solid since I set it. Recheck calibration every month until its settled.