First attach a specialty blade for cutting tin available at most hardware stores then carefully run the saw across your siding.
Cutting tin siding.
Keep cutting until you get all the way across the vinyl siding.
Repeat on the rest of the vinyl siding.
Cut along the marked line using tin snips.
Close the snips about two thirds of the way.
Open the snips and press them forward if the first snip didn t cut.
Wear safety goggles while you re cutting the siding.
It s better to use tin snips when you only have to cut a few vinyl strips as opposed to many since using tin strips tends to take longer than using a circular saw.
Run a deburring tool over the jagged edge to help smooth it out.
This will leave a jagged edge.
As you re cutting the siding avoid closing the blades on the tin snips all the way so you get a cleaner cut.
With the other begin cutting through the piece of siding with a pair of tin snips.