I dig up around the stump to expose the roots and use an axe, when I get to big roots sometimes I use a hose to soak the dirt and wash the roots clean (wait until the water drains) then I cut the roots with a chainsaw, and dig up some more using the Axe method.
If it’s a big stump I cut it into 4th’s with a chain saw once I wash all the dirt away from it with the hose... and take it out in pieces.
