If you know where the roots are you can drill into them and use a chemical of some sort.
Or, do what we did. We had some spruce trees along the driveway that kept hitting our trucks and kept snow from melting ect. They were on our land, but my aunt loved to look at them (we all lived on one long driveway ~ 1 mile total and we lived at the end). So every day we would shoot a couple 22 lr or 22 mags into them. Eventually, they turned brown, and gave us a reason to cut them. You know, for safety and all...
