It seems that the issue you might be facing is how to delete records and cascade the deletes. That really depends on your schema though. If your schema does not cascade the deletes, then you need to write the sql such that the child tables that have no child tables get deleted first, and gradually work your way up the dependency tree. Looking at user_dependencies/dba_dependencies should help you to figure out the order in which to do the delete. Just don't start deleting stuff if you don't feel comfortable writing sql, and always check your backups first.
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