Transfer attachments in PR from ECC to SRM

Hello Everybody,

We have a requirement in our project as below,

Plan Driven Procurement with Extended classic scenario... PR is created with attachment and transferred to SRM.

My question is,

How to transfer the attachment in PR to SRM ??

How to transfer SRM PO attachment(PO created in SRM) to ECC PO.

Kindly let me know what needs to be done...

Regards,

Kiran