1. Choose the HR Org. object to which you want to assign a user, e.g. the position "Accountant" in transaction PP01.
2. Choose the info type Links in the Active tab.
3. Choose Create.
4. Choose the link type, e.g. A 008 (Occupant) for the position "Accountant".
5. Choose User as the type of the linked object.
6. Choose the user name as the ID of the linked object.
7. Save the changes.
Alternatively, you can also edit existing HR Org. objects in the transaction Change Organization and Occupant (PPOME).