1. Prepare clean dustless cloth and alcohol.

2. Open the bottle cap of alcohol, put the blue bottle cap on the dust-free cloth, and pour out a little alcohol.

3. Fold the dust-free cloth into a small rectangle and the size of the bottle cap, and then put the dust-free cloth into the alcohol bottle cap and soak it.

4. spread the dust-free cloth soaked with alcohol and cover it on the oily pen marks on the floor. Wait a minute or so, and then gently wipe it with your hands to easily remove the marker marks.