Stump removal can be done in many different ways. They can be removed with an excavator, which requires the removal and replacement of dirt but leaves a stump behind. Stumps are also grinded up using attachments that remove it back to 8-16" below grade depending on attachment.
Stump removals methods come in all shapes and sizes! Removing stumps by digging them out is possible if there's access to get down deep enough for one machine or person without getting buried alive; some machines have specialized attachments like tree root grinder so you don't need to replace your entire surface area after removing roots from underneath. Oregon Land Maintenance and Reclamation can help you choose the best way to remove stumps.
Chips from this process can be left to decompose or be removed and dirt brought in to fill the crater left by grinding. A mulching attachment can also chop stumps flush with ground level, preventing them from sticking out like sore thumbs for unsuspecting hikers!