demobilize       
verb [ T ]  formal (UK usually demobilise) uk/ˌdiːˈməʊ.bəl.aɪz/ us/ˌdiːˈmoʊ.bə.laɪz/ (informal demob)
 (尤指战争结束后)使退伍,使复员
to release someone from one of the armed forces, especially at the end of a war
  He was demobilized in March 1946. 他于1946年3月退伍。