How can i lighten uneven skin tones?

Many options: There are many options to improve skin tone. For example, a retinoid (tazorac, differin, retin a (tretinoin) micro etc). I will often combine this with a prescription hydroquinone (a bleaching cream). In addition chemical peels, microdermabrasion, photofacials, laser, ipl, etc are all additional therapeutic modalities. See a board certified dermatologist that can asses your skin and prescribe whats needed.