yes, you can use the advance patrol to go back. When you come back, you can stand on the "citizen" line, not the "visitor" line. The Custom Officer will send you to a room and ask you a lot of questions. You need to have a "Temporary green card" then will get a "permanent green card". After 3 years from the date you got the "stamp", you can apply for Citizenship. And will 5 years instead of 3 years if you are divorced by then.