ORIGINAL: timbercruiser
You might try spraying them with Arsenal or Chopper when they leaf out. When they are dead and dry, burn the area and then use a heavy disc on it. If they are no bigger than that you should be able to plant a clean area this fall.
This is the best advice I've seen so far, as long as the fuels are continuous and you have the ability to contain the fire once you start it. I'd suggest spraying, burning and touch it up by whacking it once it has been burned. If there is any chance at all that you cannot contain the fire, just spray and whack.
By the way...how big of an area are you dealing with?