For Philips Norelco Sh50 Shaver

eBay Easy to replace shaving heads

1 Open the shaver by pressing the "release" button;
2. Remove the retaining rings by turning them counter-clockwise;
3. Take out the old shaving heads and carefully insert replacements; check that the heads align exactly in the setting;
4. Replace the retaining rings and secure them by turning the lock clockwise;
5. When you close the shaving head properly, you will hear it click into place.
    
Reset your shaver after replacing shaving heads

After replacing shaving heads, you can reset the replacement reminder by pressing the on/off button for more than 7 seconds. Otherwise, replacement trigger will turn off automatically after 9 successive shaves.