Go to the running water (if no running water is available go to a semi-flat area). Pick up a rock and visualize all things that make you angry, Picture them flowing out of your body and into the rock. After you clear your head of these thoughts, do the same with any thing that makes you sad. Do this with any other emotions until you have complete happiness.
After this, throw the rocks into the river (or into the flat area) and visualize these thoughts leaving forever. After this, dip your hands into the water (if you don't have a river just meditate.) and visualize all bad emotions running out of your fingers into the water and then they get swept away. After this you should be happy.