Squeeze all the juice out of the lemons. I cut each lemon into 8 parts, then squeeze each piece - this way it yields the most juice :)
Combine water with sugar in a microwave-safe bowl and microwave for several minutes, until the water is hot. Stir to dissolve the sugar.
Pour the sugar water and lemon juice into a 9-inch baking dish, and stir to combine. Put it in the freezer.
After 1 hour, rake it with fork to break up the ice crystals. Repeat raking with fork every hour until the desired consistency is reached (usually around 3-4 hours from the time you first put it in the freezer).