Antonyms for the word "re-instituting" are "abolishing," "removing," "terminating," "discontinuing," and "eliminating." These words indicate putting an end to a practice or activity that was previously in place. Whereas, "re-instituting" means restoring or bringing back something that existed before.
When we speak of abolishing something, we mean completely removing it from existence. Terminating suggests that the action is ended by someone in authority, like terminating an employee. Discontinuing is a more gradual process, suggesting that something is slowly being phased out. Meanwhile, eliminating means erasing or removing something completely, like eliminating debt.
In summary, antonyms for re-instituting are words that describe the opposite action, indicating the end or removal of something previously in practice.