How to unlink structured data store from app and delete it

[kcaluwae]

I created a structured data store for my app but the schema has changed since I created it.
I cannot update the schema to the current schema as some columns have been replaced by others.
Therefore I want to remove the data store and replace it with a new one but I don't see where I can unlink the data store from my app.  This is a prerequisite to delete the datastore.
Tx!