1. Put the lid in the correct position above the cup.

2. Insert one end of the spring into the hole of the cup cover.

3. Gently insert the other end of the spring into the fixing hole of the cup by hand or tool. Use a little force, but be careful not to use too much force to avoid damaging the spring or the cup.

4. Make sure that the spring is firmly installed on the lid and cup. You can test whether the spring works properly by gently twisting the lid of the cup.