This is assuming that the company has got to the LAST PERIOD of the year Week 52 and they should be in Week 51

To fix this 
1. Created a 'new weekly' payroll group and setup the calendar the same as current group.
2. Set the group to be in Week 51
3. Then transferred the employees from old group to the 'New Weekly' groups, re-ran the CALCULATION and sent through to HMRC an AMENDED FPS 
4. Reprint TO-DATE and THIS-PERIOD reports
5. DO NOT re transfer NL and CB if already carried out
6. Update payroll as normal and process Week 52