Please do as follows to change your employee leave entitlement:
Go to the Core module.
Click Employment Details and select the employee.
Click Career Progression and click New.
Enter an Effective Date and Confirm.
Select the new Category and click Save. (You need to check your Range Basis on your Leave module, Setup, Leave Policy. Range basis will determine the employee's specific leave allocation for progression, transfer, and promotion. If your range basis is not Category, then you need to update the Career Progression accordingly.)
Go to your Leave module.
Click Process Leave and Recalculate the affected employee.