To remove Fusion from your environment, there are two steps.
Step One: Unpublish the Fusion customization package from your Acumatica environment and delete it. If you do not know how to unpublish from Acumatica, you can refer to the help section inside of Acumatica.
Step Two: Uninstall Fusion WMS from the handheld or delete the application from the handheld. Once step one is completed, access to Acumatica will stop immediately.