Broil: if split, place crab in broiler pan, shell side down; brush with butter in favorite sauce. Place pan about 4 inches from heat; broil 3-4 minutes. Brush occasionally with butter or sauce while broiling.
Steam: place steam basket in large pot; fill with boiling water to depth of 3/4 inch. Place crab legs in basket; reduce heat and steam, covered, about 5 minutes or until crab is thoroughly heated.