Front Brake Drum outer spring

Hello Members. Question is how do I stretch that , I am guessing, the cooling spring, back on to the outside of the front brake drum once it has been removed from the drum. This is on a 65 Dart, 10 inch x 2-3/4 inch inside braking surface on the drum. Tried different methods with no success. Any advice would be appreciated. Thank you for the help. sgrip65