If a double spend is executed, what happens to the original transaction? So I think i have read enough about double spending so as to be able to execute one.

But I have found nowhere what happens to the original transaction.
A doublespend is a set of transactions which are conflicting with each other. This happens when all transactions are trying to spend some of the same UTXO for inputs. As UTXO can only be spend once, only one of the transactions of the set can be confirmed. When one gets confirmed, all the others become invalid, the invalid transaction will then be forgotten by the network at that point.

Just be sure that some of the inputs match, otherwise you're sending the payment a second time instead of creating a conflicting transaction.