delimit old positions

Hi Experts,

We have redefined the organizational structure, I have created new positions through PO13. now i want to assign it to respective employee through LSMW recording. But when i record PA40 internal transfer action, the system is not asking to delimit the old position, hence, the person is assigned to 2 positions at a same time. Pls guide me how to delimit the old position ?

ex. : Emp Name : Venkateshwarlu

Old Position : 20001304 , Org Unit : 14000020, start date : 01.01.2011, end date : 31.08.2011

New created Position : 50003876 , Org Unit : 14000020 , start date : 01.09.2011, end date : 31.12.9999

How should i delimit the old position for bulk employees at a single shot?

Pls guide me.

Thanks,

Shree NP