This Black and Decker battery powered lawnmower comes fully assembled; you just need to lift the handle upright and tighten the screws to anchor it in the upright position. No tools are necessary since there are plastic knobs that easily turn to tighten the screws. The handle also has a height adjustment. Because this is a battery powered lawnmower, the lawnmower needs charging. Make sure the safety key is removed from the top of the mower. The battery is already installed, so plug the charger into the lawnmower, and then plug the charger into a wall outlet. It is recommended to always leave the mower on constant charge.