How do international students file tax return in the US?

Answer 1

Just like US citizens. Go to your nearest IRS office if one in your town and talk to them. Also go the post office where they have returns to pick up for free. In one of the books they will have a toll free number.

Answer 2

if you're authorized to work here then i assume you have a SSN and an employment authorization card, just take those documents with your w-2 and whatever else tax document you got and go to your local h&r block or any other tax center just like anybody else.