There should be a red link in the top right corner of your facebook page that says "Export friends!" (right to the left of the "Home" link). Once you click tha

There should be a red link in the top right corner of your facebook page that says "Export friends!" (right to the left of the "Home" link). Once you click that, just follow the accompanying instructions and it should work - although be warned it takes a long time, especially if you're doing it for a lot of "Friends".