My mission this year has been to replace the negative with positive, but it by no means has been easy. One trick that helps me to always see the upside of things, is a gratitude list.
Whenever I'm feeling down or particularly mean-spirited or judgemental, i pull out my on-going gratitude list and write down one or two things on it that I am thankful to God for. This helps me to always look on the bright side of life, because let's be real, there's always something out there to be thankful for, even if it's just being thankful for making it through the day.
Try it out, and see how it helps change your perspective on life!