Complex sentence: In April 1945, the "111th division" was reassigned to the 58th army and in May 1945 moved to the Jejudo island, where it spent time until the surrender of Japan preparing a fortifications without seeing an actual combat.
Split into simpler sentences: In April 1945, the "111th division" was reassigned to the 58th army and in May 1945 moved to the Jejudo island. On Jejudo, the "111th division" spent time until the surrender of Japan preparing a fortifications without seeing an actual combat.