Remove the screw that connects the downspout's bottom elbow to the downspout; there is usually one screw but there could be two. Use screwdriver or a nut driver if the screw is a hex head to remove the screws. Disconnect the bottom elbow from the downspout.
Remove the screws from the downspout strap using the nut driver. Lean a ladder securely against the building or home. Climb the ladder and remove the screws from upper downspout straps using the nut driver. There is usually a downspout strap every 6 feet.
Unscrew and remove the screws that hold the top downspout elbow to the rain gutter's drop outlet using the nut driver. Disconnect and remove the downspout from the rain gutter.
Disconnect the downspout from the remaining elbows. Remove the screws with the nut driver. Downspouts come in solid 10-foot lengths and do not come apart.