Click on "Recharge" button on the upper left corner of your monitor display.
Click "Recharge" again to confirm.
Choose the Recharge Method (Paypal, Visa or Mastercard); confirm that account logged in was right, also select which server you want to Recharge to; select the amount you want to Recharge and then click Recharge.
Sign in with your Paypal account, or choose "Pay with my credit or debit card" if you don't have a Paypal account.
There will be a confirmation saying Recharge succes if you have completed the transaction, and Gold will be automatically transferred.