I Spoked By Phone With An Officer Of Uscis, She Said If We Decide To Change The Employer That Will Take 6 Months More... For A Decision... But Just In Case If We Receive An Appointment For The I-485.. She Said That We Can Bring A Letter Of The New Employer And All The Papers For Requirements.. My Question Is: Is This True? Or Is Necessary To Do Before...? We Are Worry If They Will Send An Appointment... Everybody Said When Is Labor Petition Is Just By Mail Without An Appointment...who Can Help Me..? Thanks...