Well, I don't know if in Pakistan is possible, but generally you need a credit card, an account at Paypal and engage the services of any company of PO BOX in your country, general with a bank.
This type of company, creates a physics mail addres in the United State, so you can buy an electronics component by the web page of the manufacture company, pay with your creditcard, then they send the component to your recent created mail box, and then you request to the PO BOX company to send you in your door house.
I hope have helped a little.
Greetings.
Mauricio.
