Starting from the highest point on the downpipe fix the clips to the wall using rawlplugs and screws.
Cut hole in gutter for downpipe.
Use the new 3 x 4 in.
Cut the tracing for the connector with a pair of sheet metal cutters.
Place the connector in the hole with the lip of the connector on the inside of the gutter.
1 1 2 x 8s screws should be sufficient to hold the clips and pipe in place securely.
Step 2 drill four holes.
Gutters over flows add downspout to bring water down from roof faster.
Again as with the gutter this can be cut easily with a hacksaw and deburred with a half round file.
Its easy less than 30 minutes and under 30 00 in parts.
Watch and learn how and stop.
You can cut out the larger hole with a tin snips or you could use an oscillating multi tool equipped with a metal cutting blade.
Start by removing the old downspout.
This is the thing that connects the gutter and downspout together so it is important that it is placed correctly and securely.
In each corner of the outline you made of the sleeve drill one hole.
On the bottom of the gutter itself take a pencil or marker and trace the outline of a sleeve.
Drop outlet that you buy with your new downspout as a template to trace an outline for the larger hole.