The recipe calls for evaporated milk, but I only have sweetened condensed. Can I use it instead?
Sure, you just have to have an appropriate recipe. Google "sweetened condensed milk pumpkin pie", you will find several recipes, including one by a major maker of sweetened condensed milk.
Take the 14 oz. can of condensed milk and and add 10 oz. of water. Wisk until mixed thoroughly. Using a couple of tablespoons less of sugar will result in an almost identical final pie.