How did Joseph balicki escape from Warsaw in the silver sword?

In "The Silver SWord" by Ian Serrallier, Joseph Balicki escapes from Warsaw by using a combination of courage and resourcefulness. After enduring the hardships of World War II and the separation from his family, he manages to find a way to travel through the dangers of the city. He takes advantage of the chaos, disguises himself, and ultimately makes his way to Switzerland in search of his wife and children. His determination and hope propel him through the treacherous landscape of war-torn Europe.