That would be a very dangerous thing to do. Trees die slowly and can suddenly fall in a storm causing injury and/or property damage. Best to just have it cut down.
Newt
One way is to drill holes in the tree (angle them down into the tree) using something like a half inch bit and make then an inch or two deep. Fill these with a weedkiller such as SBK or Garlon and for best effect seal the holes
I agree with Newt though, they may not get very big but why risk it, you can cut it down and still kill it using the method I suggest