Disconnect from Xero
To disconnect your Shopify store with Xero, go to the "Setup - Xero" section of the "Post to Xero" app.
In the "Connect to Xero" section, you will see a "Disconnect" button.
Click on the Disconnect button.
This will now disconnect your Shopify store from Xero, and remove any access previously provisioned between Shopify and Xero.
You will also see that the "Connect to Xero" section states "No account connected" once it's been disconnected.
Tip: If, for whatever reason, you've uninstalled the app, as part of the uninstall process, your connection between Shopify and Xero will be automatically disconnected.