The simplest way to disconnect Trelica from an application is to go back to the integration detail page (Admin > Integrations > Search for the application), click the menu icon on the right, and choose Disconnect:
This will stop Trelica refreshing data from this source. You can reconnect at any time, although you will need to reauthorize access or re-enter integration specific parameters.
Individual applications will also typically provide mechanisms for revoking Trelica's access. This may involve deleting or regenerating an API Key, or deleting the OAuth permissions granted.
You may want to disconnect and reconnect with different information, or another user name. Clicking Disconnect and then reconnecting will let you do this: