Cut it to length with a hacksaw and removing any burrs with a half round file.
Install gutter downpipe.
Its easy less than 30 minutes and under 30 00 in parts.
Place a step ladder under the area you are installing the downspout.
Measure in 4 inches from the end corner of.
Watch and learn how and stop.
Drill a hole in the bottom of the gutter at the 4 inch mark with a 1 inch hole saw attachment to the drill.
Fit the gutter in place which normally just clips in with the appropriate stop ends connectors and gutter outlet for the downpipe.