I hope I understand this right. It sounds like your friend's Alipay(chinese-made PayPal) is bound to your Taobao account, is that correct? You can change your tied Alipay account from your user settings menu. I'm not at my PC right now so the best I can give you is this pictorial guide in Chinese. 淘宝账号如何更改支付宝账号（已实名）_百度知道 Alternatively try googling "Taobao changing Alipay account" and see if you can find something that works.