Core HR: Implementing full HR when we are already using part for Purchasing.

Hi,

We currently use some of the HR functionality to hold employee data but only for employees which are required in the Purchasing approval hierarchy. However, I would like to understand how best we could migrate all our employees across to make full use of the HR functionality. We would key in the employee data, but some of the employees already have an HR record, albeit with an incorrect hire date.

Does anyone have any advice on whether it is possible to change the hire date of the employees we already have setup or would it be better to re-enter everyone from scratch and end-date the existing ones?