You can reset your hub to its factory state, which will erase all your account information.
To perform a factory reset of your hub:
Unplug the power adapter from the Harmony Hub.
On the back of the hub, press and hold the Pair / Reset button.
While holding the Pair / Reset button down, plug the power adapter back into the hub.
NOTE: You should see the LED light in the front of the hub flicker red.
Release the button.
The LED light will flicker until the factory reset is complete.
After you reset your hub, you'll need to add it back to your account.