Sorry, that was not what I meant.
Go to SPRO --> SAP Netweaver --> Gateway Service Enablement --> Backend OData Channel --> Service Development for Backend OData Channel --> Maintain Service.
You have to create a version 2 of your service exactly the same as your version 1. You will click on Assign Model and assign it to the version 1 of your model.
Then go to /IWFND/MAINT_SERVICE and bring your new version of the service. Remember to use the v=2 suffix in your app when calling the oData service.
That should work.
Regards,
Leonardo.