MILITARY leaders will meet late this month or in early May to determine how to streamline the nation's huge armed forces. The Central Military Commission, led by President Jiang Zemin, will meet in Beijing to discuss how to cut troop numbers by 500,000 over three years. They also want to increase spending on technology and weapons systems, Beijing sources said. They said because huge numbers of soldiers would lose their jobs, government leaders had warned the revamp must proceed cautiously to avoid social instability. Some troops would be transferred to the People's Armed Police. All military staff losing their jobs would be guaranteed social security. Meanwhile, a Beijing source said Central Military Commission vice-chairman Chi Haotian had recently been put in charge of the commission's day-to-day work, a job formerly done by first vice-chairman General Zhang Wannian. Beijing sources said General Zhang, 69, had heart trouble and could no longer handle a heavy workload.