Pull the old blade from the body of the Stanley tape measure until you see the small circular hole located on the black winding spring.
Slide the nail into the circular opening on the winding spring to hold the spring in place.
Squeeze and twist the connection between the old blade and the winding spring to remove the old blade from the body of the Stanley tape measure.
Cut along the dotted line of the replacement blade packaging with the utility knife. Do not cut through both sides of the packaging, as this will make the replacement blade installation difficult.
Bend the packaging along the dotted line you scored with the utility knife in Step 4.
Pull the end of the replacement blade from the packaging.
Push the end of the winding spring into the slot located on the end of the replacement blade.
Hold the end of the replacement blade with one hand and pull the nail from the winding spring with your other hand.
Release your hand from the replacement blade to allow the blade to load into the body of your Stanley tape measure.