Station staff (JKN) reported external window of the rear M1 A3 door shattered. Station staff (BNL) i solated the affected train door. Train was reformed with an AM peak withdrawal train. ~~~~~ 1533 Station staff (JKN) reported external A3 door window shattered. Station staff (BNL) isolated the affected train door. Train was reformed with an AM peak withdrawal train. L3 L3 1533 A3 saloon door window replaced. Security/function check - OK.  Chan GF/Alan 44296