How to delete registered model and service?

 1. Delete Project from Service Builder

2. Go to ABAP workbench and delete all generated classes and interfaces. (you may use "Go to ABAP Workbench" context menu from Service Builder classes nodes)

3. Go to: SPRO -> SAP Customizing Implementation Guide -> SAP NetWeaver -> Gateway Service Enablement -> Backend OData Channel -> Service Development for Backend OData Channel:

a.Delete service using "Maintain Services" node: provide the Technical Service Name and service version; then click on Delete Service button

b.Delete model using "Maintain Models" node: provide Technical Model Name and Model Version; then click on delete Model button.