Thanks S-daly, to rollback, please navigate to payroll > pay runs > click pay period to open, from here, select pay run actions > unlock > pay run actions > Mark all as a late submission and then option H Correction to earlier submission (this will overwrite the existing submission to HMRC so that the payroll is not duplicated for the period) > click finalise pay run - here you'll be able to set the new pay date :)