Remove the snow accumulation with a roof rake. Stand on the ground while you do this; never climb on an icy roof. Leave a small amount of snow on the roof to avoid damaging the shingles with the rake.
Remove large icicles to prevent damage to the gutters.Tap the icicle gently with a long wooden pole. Don't hit them aggressively because this might damage the roof or gutter.
Make drainage paths with hot water if you have a dormer window on your roof. Use streams of hot water to cut paths in the ice leading down to the gutters. Make multiple paths to partition the ice. Direct the hot water into the sections of ice to loosen them and make them fall to the ground.
Throw a chemical deicer onto the roof. Avoid using products that contain sodium chloride or calcium chloride because these might damage your roof. Select a product that contains calcium magnesium acetate, ammonium sulfate or potassium chloride. Urea also will work, but not as effectively.