Wash greens repeatedly until all grit is removed–it will take a lot of washing. Drain. Remove and discard large stems. Combine pork, sugar, bouillon cubes, water and margarine in a large soup pot. Bring to a boil over medium-high heat. Boil 5 to 10 minutes. Add greens. Reduce heat and simmer, covered, for 1 1/2 hours or until greens are tender.