Set the final piece of gutter on the first side of the house into the joiner to connect it to the previous piece. Snap it in place and run it down to the end of the first side of the house where it meets the corner.
Snap the vinyl hooks into the gutter and screw them into the fascia behind the gutter. Attach the hooks to the front of the gutter and the back. Space out the hooks every 18 inches down the gutter to secure it in place.
Snap a joiner into place at the end of the gutter and slide a drop outlet into the joiner. This will attach to the downspout which will run down the side of the house. Snap an end cap in place into the drop outlet at the end of the gutter.
Press the end cap in by hand. Use a right end cap for the right side of the house and a left for the left side, depending on which side of the house you are installing it on. Inspect the corner and make sure all of the pieces are attached to one another before installing the downspout.
Slide the downspout in place over the drop outlet and run it down the side of the house just as you would a normal gutter. Screw a downspout band around the downspout and into the side of the house with a power drill.