Philips SH91/51 Series 9000 Replacement Shaving Head
Reset your shaver very simply: 1. Press the release buttons and detach the shaving head holder. 2. Turn the retaining rings counterclockwise and remove them. 3. Remove old shaving heads and insert replacement (notches should fit exactly onto the projections). 4. Place retaining rings back and turn them clockwise until you hear a click. 5. Insert the shaving holder back and close.