How To Change My Wardrobe Into Indie? :)?

Hi! I love the indie style, but most of the clothes I have are pink, girly, frilly, you know...childish clothes. Most times people buy those for me. I really love the indie style though, and I don't have a lot of $$ for myself. It is summer, so I have about 1 month to alter my wardrobe. How do I do it without getting new clothes, or that many new clothes? What do I need to dress indie? Thanks a bunch. :) x xoxoxoxo