Spread the buttocks, as you do this, so the temperature changes will have the best effect on the desired area. Do this 3 times. You can come back later and do it again as needed. An alternate method, to use in less severe cases, is to sit in a bathtub of 10-12 inches of hot water. Do this 3-5 times a day.
Cranberry poultices are helpful.
Blend a handful, wrap a tablespoonful in cloth, and lay against the area. Change an hour later, and repeat when you wish. Dab lecithin on the area, as you would Vaseline. An ice pack to that area may also bring relief. Peel a garlic bulb and scrape it, to get the juice, to flow.