The process is really quite simple; On a piece of paper, write down anything and everything you want to release to the Universe. It could be about a really bad day you recently had, it could be an emotional state you've felt stuck in or attached to. If it doesn't serve you well, get rid of it!
Once you have written everything down, take that piece of paper outside under the full moon. Very carefully, light that paper on fire, either holding a tray/plate underneath it or over a fire pit. As the smoke rises, say out loud or inwardly from your heart; "I release to the Universe all that doesn't serve me well, I am free."