The words that are antonyms for "fixing with" include separating, detaching, disconnecting, and disengaging. When we use the word "fixing," we usually refer to repairing something, solving a problem, or correcting an issue. However, there are times when we need to separate or detach things instead. For instance, if we have a broken appliance, we may need to detach it from its power source before fixing it. Disengaging means to remove from engagement or a state of being attached, which may be required in situations such as breaking off a relationship, business partnership or terminating a contract. In conclusion, while "fixing with" can imply connection or attachment, its antonyms describe the opposite act of separation.