Edit: if this is at all unclear, I'll simply turn over the login credentials to the sender, no transfers involved.
i hate to be a drag, but in the interest of full disclosure, doing this is one of restricted activities pointed out in paypal's user agreement:
you will not:
ab.) Reveal your Account password(s) to anyone else, nor may you use anyone else's password. We are not responsible for losses incurred by you including, without limitation, the use of your Account by any person other than you, arising as the result of misuse of passwords; or
https://cms.paypal.com/va/cgi-bin/?cmd=_render-content&content_ID=ua/UserAgreement_full#6. Restricted Activities