Tan on neck?

When I was small in middle scjooo I would skate all day everyday so my neck would be very dark since I stay in the sun for like 10 hours a day. I used to skate from 9am-8pm. Now I stop skating for like 2 years and I’m still in highschool because the tan in my neck wouldn’t go away. The back of my neck is extremely... show more When I was small in middle scjooo I would skate all day everyday so my neck would be very dark since I stay in the sun for like 10 hours a day. I used to skate from 9am-8pm. Now I stop skating for like 2 years and I’m still in highschool because the tan in my neck wouldn’t go away. The back of my neck is extremely darker than the front of my neck. How do I get rid of the tan