Replacing the broken string on your Poulan chainsaw is easy, and doing it yourself will save you some money.
Use your scrench to loosen the top cover and remove the four screws holding the fan cover in place on the left side of the saw.
Cut the new string to the same length as the old one and insert the loose end through the hole in the cover.
Rotate the starter pulley assembly clockwise for five revolutions with your hands. The screw should be on the left side.
Loosen the screw, run the new string through the hole next to the screw and form a loop around the screw.
Tighten the screw and let go of the pulley. The spring will make it rotate counter-clockwise into the correct position.
Put the fan cover back on and tighten the top cover.