I've removed black spots from my space successfully using lemon juice and a cotton ball.
I took some lemon juice from a lemon and soaked a cotton ball with the lemon juice and then I took the cotton ball soaked with the lemon juice and applied lemon juice to the spots on my face.
I then waited for the lemon juice to dry on my face and then washed my face off.
I had to apply the lemon juice to the spots on my face for two weeks everyday and then the black spots on my face disappeared.