Cut down the weeping willow using the chainsaw. To make stump removal easier, make the cut as close to the ground as possible. Wear gloves and safety glasses as you work.
Paint the stump with a nonselective herbicide. The herbicide will sink into the stump and travel throughout the willow's root system. Using a paintbrush prevents the herbicide from harming nearby plants and flowers.
Continue painting nonselectice herbicide onto the stump every other day for two weeks.
Use a stump grinder to remove the remnants of the willow's stump.