Just run the same brute force as for error 1, but this time run it inside a loop bruteforcing all possible parity bit positions.
[https://github.com/blatchley/CTF_Writeups/blob/master/2020/NACTF/crypto/CryptoWriteups.md#error-2](https://github.com/blatchley/CTF_Writeups/blob/master/2020/NACTF/crypto/CryptoWriteups.md#error-2)