The first thing to do is to cut the stump as close to the ground as you can. Depending on how big the tree is, you should drill anywhere around a dozen or so holes in the stump. The holes should be drilled with a one-inch drill bit and drilled to a depth of around 10 inches.
Then mix rock salt or Epsom salt with a small amount of warm water and fill the holes with the solution. After doing so, cover the whole stump with a dark tarp or a black trash bag for a few months. Although it is unlikely that any saplings will pop up, it is a good idea to keep on the lookout for them and to remove them if you see them.