Complex sentence: Once back in Germany, they made efforts to appear less radical--distanced themselves from others and stopped attending extremist mosques, changed their appearance and behavior, and Jarrah was behaving more the way he did when he first met Senguen.
Split into simpler sentences: Once back in Germany, they made efforts to appear less radical: they distanced themselves from the others, stopped attending extremist mosques, and changed their appearance and behavior. Jarrah, for example, began to behave more the way he did when he first met Senguen.