This is how to delete a post or comment programmatically

curl http://127.0.0.1:8093 --data '{"jsonrpc": "2.0", "method": "sign_transaction", "params": [{"operations": [ ["delete_comment", {"author": "username", "permlink": "re-to-some-timestamp-z", "required_posting_auths": ["username"]}] ] }, true], "id": 1}'