Attach the downspout—that vertical pipe that takes water to the ground. This is where you discover that pre-cut downspouts are always exactly one foot too long. You’ll need a hacksaw. Cutting metal with a hacksaw makes your arms feel like noodle spaghetti, but the ping sound when the blade breaks is a rite of passage.
Point the downspout away from your house. Aim it at your neighbor’s petunias if you want a feud, or at a splash block—a little plastic ramp—if you want to keep your basement dry.