To open head assembly: Gently push the small plastic tabs at either end of the foil carrier. It should easily detach from the shaving head. To reassemble, snap the new foil carrier into position. Attach the shaving head. To replace cutters: Open shaving head (as above). Grasp cutter between forefinger and thumb and pull upward. Place cutter into oscillator tip. Gently push to click into position.