To remove old paint on stucco cement, get a high pressure sprayer. Water blasting is quick and clean, and much easier to do than sand-blasting. You can rent one from a tool rental dealer or large paint store.The sprayer needs to be able to develop around 1500 p.s.i.f you own a home whose stucco finish siding has been painted, there will probably come a point when you want to repaint, and have to remove the existing paint entirely.