Remove your spark plug wire to prevent electrical shock.
Remove the rubber T-shaped handle from your old pull string. Slide it up, untie the know and slip it out through the rear of the handle.
Locate the screws or bolts that hold your snow thrower's outer cover in place. There may be screws, small bolts or even hex nuts holding your cover in place depending on the brand of snow thrower that you have. If you are unsure or it's not evident when you look at your thrower, you may need to consult your owner's manual.
Pull out the old recoil starter cartridge after you remove your thrower's cover. Pry it out with a screwdriver if you cannot remove it by hand. Also, depending on your make of thrower, there may be two screws holding it in place. If this is the case, remove those screws with a screwdriver and then pry the cartridge out.
Spool the new starter string around the pulley on your replacement recoil starter cartridge. Leave enough slack in the cord to slip it through the cover later.
Snap the new cartridge into place.
Slip the starter rope through your throwers cover. Replace your thrower's cover along with its retaining screws or nuts.
Slip the end of the pull cord through the rubber T-shaped handle and tie a knot.
Replace the spark plug wire.