Cut the leg(s) off of a pair of pantyhose.
Fill the (each) leg with de-icing salt. For de-icing gutters, magnesium chloride de-icing salts are best. They are the safest for the environment and cause the least damage to structures and underlying plants. Tie the cut end of the pantyhose to keep the magnesium chloride inside.
Climb up onto the roof. Lean a ladder against the wall at a 75-degree angle. Ensure that the ladder is on a flat, solid level surface. Check that the ladder's locks are secure. The ladder must extend 3 feet above the edge of the roof. Never stand on the top three rungs. If possible, have a partner hold the bottom of your ladder as you climb.
Lay the leg of the pantyhose over the top of the ice on the gutters. For long ice patches, apply a length of pantyhose every 2 feet or so. Climb down the ladder and move it as needed. Always keep your body centered in the middle of the ladder. Do not lean over either edge of the ladder.
Remove the pantyhose once the ice is melted. This may take 20 minutes to one hour.