What is the easiest way to remove a tree stump?
A stump grinder. Sometimes you can rent small ones, or hire someone who has one. However, if you want to do it yourself, you’ll need to dig and cut roots and dig some more and cut some more roots, etc. I did that a few times, only I was lucky enough to have a tractor that I could use to pull on the stump to help lay it over and make it easier to cut the roots. If you have enough time, you can try to rot it out of the ground by drilling big holes into it and pouring some high nitrogen fertilizer into them, and then keep it wet for a few years.