Measure the area of the room with a tape measure to determine how many feet of crown molding will be needed for installation. Measure the first piece of crown molding to the length of the first wall and mark where the cut will need to be made.
Slide the piece of molding into the saw upside down along the fence. This will allow for the proper angle cut to be made. Turn the blade of the saw to 45 degrees in the desired direction for the cut. Line up the blade with the mark on the crown and pull down on the lever to cut through the molding.
Measure the length of the second wall and mark it on the crown molding. Turn the blade of the saw to 45 degrees in the opposite direction of the first cut and line up the blade with the mark on the molding. Cut the second piece just like the first was cut.
Butt the two pieces together at the corner to make sure they fit properly. Hammer the crown in place. Insert a finishing nail every six inches down the center of the molding. Move down each piece until they are secure to the ceiling. Measure from the end of the second piece to the wall and mark the same distance on a piece of crown so a straight cut can be made.
Turn the crown upside down and slide it into the saw. Turn the blade of the saw to 90 degrees and cut the straight pieces just like the previous pieces were cut. Line up the straight pieces along the wall and install them in the same manner. Continue around the room until all of the crown molding has been installed.