How To Flash Samsung Galaxy S3?

[AC Question]

I Have Samsung Galaxy S3 SGH-I747M I Want To Flash It To The Stock ROM But Its Micro USB Port Was Damaged And Does Not work And My Phone Is Not In The Bootable Condition But It Will Be Able To Boot In To Recovery Mode And Download Mode And I Tried To Flash IT I Download Firmware From SamMobile And Extract It And Boot My Phone Into Recovery Mode Then I Locate The Firmware File Then Install It But It Failed Please Help Me How I Can Flash It By Its Own Recovery Mode