Marilyn, I used a lopper type pruner, put it around the trunk without closing it all the way, and moved it up and down til the bark was scraped off and it had dug into the trunk a bit. Then I changed the angle and repeated until I had scraped all the way around. I did this in two places just to be sure I got it good.
After I had written this article I found another buckthorn in my lilac along the alley. For that one I used a sharp gardening knife to do the same since it was not on a hill and I could reach the trunk easily.
Does that answer your question adequately?
