there is a lever on the left side of the shaft its silver with a tab and pic of a button hole on it. Pull the tab down, the buttonhole attachment will hit it and do a return for the other side of the hole. You stick a button into the slot and push it tight, if the button is a thin one I usually remove it and push the slot closer together for a smaller hole.
Also I will dial down the thread tension (2-3) so the zigzags are more even on the underside.
hope this helps
Rainy
May 2015