How Can I Get The Skin On My Neck Back

How can I get the skin on my neck back to normal skin tone? I'm 20, 6', Male, 180ish pounds. After years of not moisturizing my neck, it gradually got darker than my face, significantly! How can I go about bleaching and restoring it's natural color. I've been moisturizing for a year now and I feel like I've gotten it to the lightest color I can get just using that method. Is Mequinol safe? A lady at a market in Chinatown offers to lighten my skin tone for $24 a tin.