To Edit a Dependency you can do so by clicking into the Component Details and navigating to the dependency tab. From here you can edit existing dependencies or create new ones.

Dependencies can either be finish to start or start to start. If a Component already has dependencies added to it then they will show in the top section of the screen, under Current Dependencies. Potential dependencies are listed in the bottom section of the modal window. From here either Predecessor or Successor Dependencies can be added.