The phrase "let stay" implies allowing something to remain in place or continue in a particular state. Some antonyms for this phrase would be "remove," "evict," "dismiss," "expel," or "oust." These words describe actions that involve actively pushing something out or away. Other antonyms could be "change," "alter," "shift," "transform," or "modify," which suggest a desire to adjust or manipulate a situation. "Stop," "halt," "prevent," and "discontinue" might also be considered antonyms, as they describe actions that disrupt or put an end to something. Overall, there are many antonyms to "let stay," each describing a different approach to handling a particular situation.