How do i even chargeback

so basically i reported a scam ( my first time </3 )
http://www.sythe.org/report-scammer/1796101-scammer-cehjok.html
as you can see the guy that reviewed the ban said i can chargeback, but i dont know how to do that!

if you friendly folks could explain the best way to get a successful chargeback on a runescape account trade it would be greatly received, thanks

PS if there is a better sub-forum to hold this post in, please move it

 

Go to the payment you sent, and claim it back via unauthorised access (saying someone else had access to your paypal & bought virtual goods) and sent the payment.