Complex sentence: This task was made more difficult though by a torrential downpour on 6 November, nevertheless they were eventually able to establish themselves around Pal Mal Mal plantation and patrols were sent out to locate the Japanese.
Split into simpler sentences: This task was made more difficult though by a torrential downpour on 6 November. After establishing themselves around Pal Mal Mal plantation patrols were sent out to locate the Japanese.