When it comes to redoing or repeating a task, there are several synonyms for the phrase "do over again." One common alternative is to "start over," which implies a complete reset of the task. "Retry" or "try again" suggests another attempt at completing the task, perhaps with a different approach or strategy. "Redo" or "rework" could apply to adjusting or improving an already completed task. Another option is to "recapitulate," which means to summarize or repeat a previous action. Ultimately, the choice of synonym will depend on the context and the desired level of specificity or emphasis.