need to get it to a tablesaw. turn the blade around backwards. DO not push it backwards thru the saw instead of turning the blade around. slowly feed it thru. to polish the edges up you can use fine sandpaper or a palm sander. Use a mask goggles and protect your skin from flying particles of polycarbonate. The dust is not good for your lungs or your eyes in fact it can irritate your skin and leave you itchy very itchy.
we use this method to cut plexiglass sheets for hockey. works well and doesnt chip chunks out of the edges.
If you cant get it to a tablesaw you can use a hand power saw the same way. But I will not recommend this bec its dangerous and can kick back and hurt you seriously. Tablesaw is best.