Disconnecting your Shopify store from Shiptheory, should you want to, is very straightforward.
From your Shopify store
Once logged into your Shopify store's admin panel, go to the Apps and Sales Channels settings and click the Remove option next to the Shiptheory app:
Once logged into your Shiptheory account, select the Manage Channels option from the main menu. Find your Shopify Stores instance and click the red delete icon:
If you have any further questions, just reach out to the Shiptheory support team!