Open your dashboard and click the pencil icon on any link. You can change:
Destination URL: where the link sends people. The short link itself stays the same, so anything you have already posted keeps working and now points to the new destination.
Status: active or paused.
Subreddit tag.
Advanced settings: preview title, description, image, Google Analytics ID, Meta Pixel ID.
The one thing that cannot change is the link path. If you need a different path, create a new link.