How to win a Paypal Dispute?

It depends on the nature of the chargeback. If you want to avoid chargebacks, having them provide you a scan of their valid ID through their paypal email can greatly help. Generally speaking, those looking to chargeback won't risk it, so for future reference, try doing that.

As per the current situation, if it's an unauthorised claim, it may be extremely hard to get it back, especially if they used a VPN of some sort.