For the rolls, dissolve the yeast in the warm milk in a large bowl. Add the sugar, margarine, salt, eggs, and flour, and mix well. Knead the dough into a large ball, using your hands dusted lightly with flour. Put in a bowl, cover and let rise in a warm palce about 1 hour or until the dou gh has doubled in size. Roll the dough out on a lightly floured surface. Roll the dough until it is ap proximately 21 inches long and 16 inches wide. It should be about 1/4 inch thi ck. Preheat oven to 400 F. For the filling combine the brown sugar and cinnamon in a bowl. Spread the softened margarine evenly over the surface of the dough and then spr inkle the cinnamon and sugar evenly over the surface. Working carefully from the top (a 21 inch side) roll the dough down to the bott om edge. Cut the rolled dough into 1 3/4 inch slices and place 6 at a time, evenly space d, in a lightly greased baking pan. Bake for 10minutes or until light brown on top. While the rolls bake, combine the icing ingredients. Beat well with an electric mixer until fluffy. When the rolls come out of the oven, coat each generously with icing.