HDI artifacts are created, deployed and undeployed as part hdi deployer process, however sometimes we may have to drop some db objects that don't exist in design time. In that case, dynamic sql in a wrapper stored procedure is an option. Reference code can be found in the github link below.
https://github.com/ssurampally/hana-c...
You can also refer to my initial session on this topic. • How to delete/un-deploy a DB object f...