回複：關於綠卡上出現錯誤的問題

我收到綠卡後發現性別出現錯誤，女的寫成男的，請問通過何種途徑解決問題？要多長時間？非常感謝您的解答。
-File I-90 to get the replacement. and explain the error in the cove letter. You may not need to pay the fee. See this USCIS website for details:

http://www.uscis.gov/portal/site/uscis/menuitem.5af9bb95919f35e66f614176543f6d1a/?vgnextoid=b3f7ab0a43b5d010VgnVCM10000048f3d6a1RCRD&vgnextchannel=db029c7755cb9010VgnVCM10000045f3d6a1RCRD