chart: { margin: [0, 0, 0, 0], spacingTop: 0, spacingBottom: 0, spacingLeft: 0, spacingRight: 0 }, labels:{enabled:false}, legend: { enabled: true, width:1000, equalizeRowsColumns:true, panel:{ side:"top", align:"center" } }
Here is an example:
http://jsfiddle.net/t43poeb6/