Complex sentence: On October 31,1527, they sailed from Lazaro Cardenas, Michoacan, New Spain the three ships heading to Pacific, crossed the South Sea, toured the northern coast of New Guinea, which was named "Isla del Oro".
Split into simpler sentences: On October 31,1527, they sailed from Lázaro Cárdenas, Michoacán, New Spain. The three ships crossed the South Sea (Pacific) and toured the northern coast of New Guinea, or "Isla del Oro".