Start by removing the old downspout.
Cut hole in gutter for downpipe.
Clean the area around the hole with a shop rag inside the gutter and ensure that the area is dry.
Drop outlet that you buy with your new downspout as a template to trace an outline for the larger hole.
Starting from the highest point on the downpipe fix the clips to the wall using rawlplugs and screws.
Use the new 3 x 4 in.
Cut the tracing for the connector with a pair of sheet metal cutters.
Step 2 drill four holes.
Its easy less than 30 minutes and under 30 00 in parts.
Place the connector in the hole with the lip of the connector on the inside of the gutter.
Again as with the gutter this can be cut easily with a hacksaw and deburred with a half round file.
In each corner of the outline you made of the sleeve drill one hole.
Gutters over flows add downspout to bring water down from roof faster.
Watch and learn how and stop.
1 1 2 x 8s screws should be sufficient to hold the clips and pipe in place securely.
How to cut and install a gutter outlet.
On the bottom of the gutter itself take a pencil or marker and trace the outline of a sleeve.