[Solved]-How to set highchart legend style?-Highcharts

This is a little hacky (maybe I've just been using d3.js too much lately) but you could modify the SVG on the fly:

, function(chart){
    // remove the line and rect
    $('.highcharts-legend-item path, .highcharts-legend-item rect').remove();
    // add in your own elements
    $('.highcharts-legend-item').each(function(i, obj){
        var circle = document.createElementNS('http://www.w3.org/2000/svg', 'circle');
        $(circle).attr({"r":10,"fill":"red", "cy": 10});
        $(obj).append(circle);
    });
});

Fiddle here.

worked out this now.

see http://jsfiddle.net/ttxvpduv/2/

   Highcharts.seriesTypes.line.prototype.drawLegendSymbol = 
     Highcharts.seriesTypes.column.prototype.drawLegendSymbol;