1. Press the buckle to open the protective door of the lower protective mirror
drawer;
2. Pull out the lower protective mirror drawer;
3. Close the protective door of the lower protective mirror drawer to prevent
dust from entering;
4. Remove the pressure ring on the protective lens;
5. Replace the lower protective lens;
6. Open the protective door of the lower protective mirror drawer;
7. Insert the lower protective mirror drawer with lens into the inside of the
cutting head.