You have created a signature collection but you made a mistake when writing the name of a signer. You want to correct the name of the signer without having to cancel the current transaction.
This is not possible. The document already signed contains a wrong name of one of the signatories. The other signatories will have signed, while one of the identities was wrong. You need to create a new signature transaction in order to generate a corrected document that all signatories will sign again.