Transfer of Customer balance from one profit center to another profit cente

Hi,

Actually we are working in SAP version 4.7, and now i want to transfer some accounting document from one profit center to another profit center like in a customer a/c lots of documents are showing in different profit balance and right now i want to change the profit center in some documents, pls advice how can we do the same in Detail if possible provide any user manual related to that.

Thanks & Regards

Sandeep