ezPaycheck payroll software does not allow customers to edit the SSN. All data inside database is linked by SSN and the change of SSN may cause tax calculation error.
If you entered an employee with wrong SSN, please
1) Backup the data first
http://www.halfpricesoft.com/articles/sb-payroll-backup.asp
2) Delete this employee from employee list (All checks associated with this SSN will be deleted also)
3) Add this employee with the correct SSN again
4) Add the paychecks