If you need to disconnect from Xero for any reason, you can do this from the Xero dashboard by clicking the Disconnect from Xero button.   Disconnecting Xero does not remove the default chart of account, tax, currency and other in

If you need to reconnect Xero to WorkGuru, click the Connect to Xero button (Accounting -> Xero)

Xero will remember if it has been previously connected to WorkGuru.  Because of this, after signing into Xero, it will display a slightly different confirmation window from the first integration:

Instead of selecting the Xero organisation, it will prompt you to continue the integration with the previously connected organisation.   You only need to use the organisation dropdown if you are connecting WorkGuru to a new Xero organisation. Click Continue with 1 organisation to complete the connection.   It has completed successfully when you return back to the Xero dashboard.