The phrase "doing over again" refers to the act of redoing something from scratch or starting over with a task. There are several synonyms for this phrase such as restarting, repeating, remaking, remodeling, renovating, recasting, reproducing, re-executing, reiterating and re-creating. These synonyms convey the sense of repeating a task or action to achieve a better outcome. Whether you are fixing a mistake or simply improving your performance, using any of these synonyms will help you convey the idea of starting over and doing something again with renewed effort and focus.