Lay the plastic wood panel on a flat surface. Hook the tape measurer over a side of the plastic wood panel, and measure across the panel. Mark with a pencil the width of panel you wish to cut.
Lay the plastic wood panel on the table of the horizontal panel saw, and align it with the guide of the saw, which will direct the panel and keep it moving parallel to the saw blade. Reference your saw's instruction guide on where the mechanism is that raises and lowers the saw blade. Raise or lower the saw blade until the saw blade's height is an inch above the top of the plastic wood panel.
Turn the horizontal panel saw on, and run the plastic wood panel along the guide of the saw. Keep your hands on the plastic wood panel. Make sure your hands are on both sides of the saw blade, at least six inches away from the blade. Use a hand saw guide if the distance between your fingers and the saw blade is less than six inches. Apply downward force, and keep the plastic wood panel along the guide as you push it through the saw blade. Shut off the saw after the plastic wood panel is fully cut by the saw blade and is on the other side of the table saw.
Affix the plastic wood panel into the stationary vertical frame according to the directions found in your specific vertical saw's instruction booklet.
Align the plastic wood panel to the ruler that follows the frame of the vertical panel saw. If the saw beam has a digital measurer, then it does not matter where you align the plastic wood panel on the vertical frame.
Move the saw beam of the vertical panel saw to where you wish to make your first cut along the ruler on the frame or when the digital read-out on the saw beam reads the measurement you wish to cut. Pull the trigger on the saw beam to turn the saw on, and run it vertically upward along the plastic wood panel cutting the piece you want.