Follow the steps below to de-activate a ModelRisk license:
1. Go to ModelRisk Ribbon -> Help -> About ModelRisk
2. Click “Deactivate license…”
3. Confirm de-activation
4. A list of de-activated ModelRisk options will appear. Click OK to continue
5. Re-start Excel to complete license de-activation.
You can also find additional information in the installation guide: https://www.vosesoftware.com/Docs/ModelRIsk-Installation-And-Uninstallation-Guide.pdf