Use your measurements for the counter top dimensions, add an extra inch for overhang and mark the cutting line on the laminate with a straight edge and pencil. Using a heavy duty metal carpenter's square held on the line as a guide, run the carbide-tipped scoring tool over the line several times, making a deep score.
Grasp the laminate with both hands and make a clean break along the score line.
Cut off the 1-inch overhang once the laminate is glued to the counter top. Use a laminate trimmer if you can gain access to one. Simply roll the trimmer along the sides of the counter top, making sure to keep the base flat while you do so, and you will get a perfect trim.
Use a circular saw in the absence of a laminate trimmer. Mount a narrow, carbide-tipped saw blade with at least 40 teeth on the saw. Mark a cut line on the top of the laminate, and apply a strip of masking tape along the cut line to protect the surface and also to stop any chipping that may be caused by the saw blade.
Draw the cut line again on top of the tape. Use the rip fence for your saw to guide you down the cutting line, and cut in a slow, steady motion.
Smooth off rough edges with a file, working in a downward direction. Finish the edges with sandpaper.