1. Measure the screw hole of the door closer first, and then drill the corresponding screw hole on the door with an electric drill, as shown in the figure.
2. Align the door closer with the drilled screw hole, and then lock it with the screw, as shown in the figure.
3. After installing the door closer, install the parts of the door closer, as shown in the figure.
4. Install another part of the door closer on the door panel as shown in the figure.
5. Put the two parts together and lock them with screws.
6. done.