Complex sentence: The French were unable to destroy the Viet Minh forces and most of the 40,000 guerrillas escaped through gaps in the French lines, including Ho Chi Minh and his staff with General Vo Nguyen Giap.
Split into simpler sentences: The French were unable to destroy the Viet Minh forces with most of the 40,000 guerrillas escaping through gaps in the French lines. Among them were the leader Ho Chi Minh and his staff with General Vo Nguyen Giap.