Impossible even if you are in U.S.
2)大概需要多少钱?
If you do it by yourself you need to prepare 1-2 grand.
3) 请律师所办要多少?
You can spend some money(about $50-$100) consauling with an attorney but not necessary to let them proceed your application. They just staple all the documents prepared by you. Don't waste that money.
Good luck!