Modifying an agent not owned by me

As an admin I'm unsuccessful in modifying an agent not owned by me. When i look at the documentation for Agents, I see the following:

• You cannot modify another user's agents if the agent is set up to run as the owner's credentials. For example, even if an agent's permissions are modified, users will not be able to change or delete the agent.

How can an admin modify an agent in the absence of the owner credentials used for running the agent?