How to install the return spring

The installation diagram is as follows:

Tools/raw materials: tape measure, return spring.

1. Put the button and spring shown below into the blue groove as shown below.

2. Put it in, as shown in the figure below.

3. If the tape measure is redundant, it should be rolled back. When rolling, be careful not to let the tape measure or wire come loose. The long rod of the white button should be embedded in the groove of the blue round hole, as shown in the figure below.

4. Cover the casing, as shown in the figure below.