Removing a already setup custom domain involves in very few simple steps,
Login to your LocalOps account, if you do not have LocalOps account already then signup here
Go to App Environments list page and click on the App Environment for which you have to remove custom domain.
Click on Custom Domain tab to open custom domain settings section.
In the custom domain settings section, you will find the App Environment's current custom domain (if already setup).
Click on "Reset domain" button
Removing a custom domain will create 2 Ops (Operations). First operation will deploy the original LocalOps generated URL as App Environment's URL and the second operation will delete the previously user set custom domain.
Wait for both the Ops to complete. Once complete your App Environment's URL will be reset to the original LocalOps generated URL.