Clean the siding around the hole with vinyl siding cleaner or dish detergent and water then dry the siding.
Cutting hole in vinyl siding.
Place a strip of siding on the work table and align the place you plan to cut it with the edge of the table.
Use tin snips or a rotary tool to make curved cuts.
This is a trick on how to cut vinyl siding the quickest and easiest way without breaking or chipping it.
The best way to cut vinyl siding circular saw.
A hole saw tin snips etc will slice right through it.
A clean way to cut vinyl siding is to score it with a utility knife and then bend the vinyl at the score.
It should snap apart.
You can also use tin snips to make crosscuts.
Fit a circular saw with a fine toothed plywood cutting blade.
Cutting the vinyl siding is easy.
That said the hole is the least of your effort.
Cut a scrap piece of siding to a length that is several inches longer than the hole.
When we cut with a circular saw we often install the blade backwards to minimize ripping and tearing of the vinyl.
When making longitudinal cuts score with a knife and break along the score line.
For the smoothest cuts put the blade in.