How to update Supplier Adress change from Purachasing to iSupplier

Steps:

1. The supplier was defined in Purchasing
2. The supplier has acces to iSupplier Portal
3. The supplier sites are already created from Purchasing to iSupplier.
4. A change in the adress line was performed by the buyer in the Supplier sSite window in Purchasing.
5. The buyer want to update this change into the adress book already created in iSupplier.

 I can update  adress change from iSupplier to Purchasing, but I don''t know how to update an adress change from Purchasing (supplier Entry)  to iSupplier Portal.

Any help will be appreciated!