Whether because unfixable gaps have formed between pieces of the current window trim or because wear and tear have taken their toll on the wood, replacing the trim is sometimes the only option. Replacing window trim, assuming that you wish to maintain the same style, means removing the current trim, matching it with new wood, measuring, cutting and reinstalling the pieces. With the right tools, it can be done in a day.
Removing the Old Window Trim
Begin by removing the current window trim by gently working a pry bar between the wood and wall. The trim should only be fastened with finish nails, so it should pry off easily.
Prepare the New Window Trim
Next, measure and mark the replacement pieces to the appropriate length. Remember, if the 4 pieces are flush on the inside edge all around the window, if properly cut they will match up on the outside as well.
With your miter saw, make the necessary 45 degree angle cuts. Check to see that each corner makes a 90 degree angle. Stain or paint the pieces before you attach them to the window frame.
Place the New Window Trim
One piece at a time, make sure the trim is in the right spot and hold it in place with several strips of tape. After you have made any necessary adjustments, secure each piece with finish nails.
With precise measuring, cutting and reinstallation, replacement window trim can be installed in a short amount of time.