回复：关于绿卡上出现错误的问题

我收到绿卡后发现性别出现错误，女的写成男的，请问通过何种途径解决问题？要多长时间？非常感谢您的解答。
-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