You can edit a baseline for students manually by going to DATA > select KS3/4 and cohort > KS2 / EAP > Baselines.
Once you are here, click on the Grade Count for a subject this needs to be added for, e.g. KS2 Maths Scaled Score. This will show a list of students who already have a score in this subject.
To add a new score click 'Edit Grade' at the top of the table.
Next, enter the updated value in the textbox and click Save.
This can then be repeated for another baseline subject, e.g. KS2 Reading Scaled Scores, if the student also has an updated score for this.
For the change to take effect in the reports you will need to republish KS2/EAP data as well as all datasets/assessments in GRADES > Publish Grades.
Thanks for reading!