You will need the Full Write People permission to perform this action.
While you cannot reset a user's password yourself, you can send them an email with a link for them to reset the password. To do this, navigate to the person and click on "Change username/password."
In the pop up, click on "Send reset password email" to send them the email. This button will only appear if they are a user in the system.
Helpful Tips
You can also reset a password from the login screen. You will need the user's account email address.
If they say they did not receive the email, advise them to check their spam folder.