INJURED AND COWORKER WERE CHANGING A LATCH ARM ON A SUPERIOR HIGHWALL MINER BEAM, INJURED WAS HOLDING NEW LATCH IN PLACE WHILE COWORKER ATTEMPTED TO INSERT THE HOLDING PIN. THE PIN WAS NOT PROPERLY ALIGNED AND WHEN THE PIN WAS REMOVED THE LATCH FELL CATCHING INJURED'S FINGER BETWEEN THE LATCH AND THE BEAM CAUSING INJURY.