Put on work gloves and goggles before beginning.
Pull off any storm windows that may be on the outside of the window. The method will depend on the style of storm window, but usually you just pull them away from the sash.
Tape the inside glass with masking tape. Apply the tape strips in a crisscross pattern over the window surface. This is a safety precaution that will keep shards from flying out of the frame.
Take off any trim surrounding the frame with a pry bar and remove the glass. In some cases, the easiest approach to taking the glass out is to break it carefully. Lay a disposable tarp under the window on both sides of the wall so you can catch falling pieces. Crack the glass gently with a hammer and then pull on the tape to remove it from the frame.
Pry out the nails on the inside of the frame by sliding the notched end of the bar under the nail head and applying pressure. Once the nails are off, you can pull the frame out of the wall.