回複：怎樣吊銷綠卡？退回移民局是嗎？還是2年不來美國自動吊銷

go to US consulate, they will let you fill out I-407 and forward it to DHS to be placed in your A-file. In this case, you don't have to set foot in US at all and still get official paper proof of GC abandonment.