Installing a door may seem like a straightforward process, but if the door does not fit precisely into the door frame, then a little extra work may be involved. Trimming the door may require reducing the door's width, a job you can do yourself and therefore save the money it would take to hire a professional. All you need are a few simple tools.
Measure the width and height of the door frame. Subtract 1/4 inch from both the height and width. These new measurements represent the necessary dimensions required by the door to fit properly into the door frame.
Mark the measurements on the door to determine how much width must be trimmed from the door, using a pencil. Tape over the marked lines with painter's tape.
Position the blade of a utility knife against the top of the door, at the outer end of your painter's tape. Score a line down each side of the door by running the utility knife down the edge of the tape. The score line will help prevent the wood from splintering later when it is cut.
Place the door on a cutting bench. Align the score line with the cutting blade of the circular saw.
Switch on the circular saw and move the door forward to help the saw blade cut through the wood. Repeat this step with the opposite side of the door. Remove the painter's tape.