chart.series[name].remove()

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/data.js"></script>
<div id="container" style="min-width: 400px; height: 550px; margin: 0 auto"></div>
<button id="button_natural" class="autocompare">Show Natural Sum</button>
<button id="button_human" class="autocompare">Show Human Sum</button>
<pre id="csv" style="display:none">
</pre>

JavaScript

$(function() {
    $('#container').highcharts({
        chart: {
            renderTo: "container",
            type: "spline",
            marginLeft: 40,
            marginBottom: 60,
            marginTop: 100,
            marginRight: 200,
            alignTicks: false,
            animation: {
                duration: 1000
            }

        },
        colors: ['#80b1d3', '#7d7d7d', '#d1d756', '#fccde5', '#bebada', '#b3de69', '#fdb462', '#fb8072', '#8dd3c7', '#d34dcb'],
        title: {
            text: "xxx",
            align: "center",
            y: 20,
            x: 0,
            style: {
                fontSize: "28px",
                color: (Highcharts.theme && Highcharts.theme.textColor) || "black"
            }
        },
        subtitle: {
            text: "",
            align: "center",
            x: -40,
            style: {
                fontSize: "13px",
                color: "#666666"
            }
        },
        xAxis: {
            tickWidth: 0
        },
        yAxis: {
            title: {
                text: "xxx",
                align: "high",
                rotation: 0,
                textAlign: 'left',
                x: 10,
                y: -20,
                style: {
                    fontWeight: "bold"
                }
            },
            gridLineWidth: 0,
            min: -0.5,
            max: 1.1
        },
        credits: {
            href: "",
            text: "",
            position: {
                x: -185
            },
            style: {
                fontSize: "8px",
                color: "#666666"
            }
        },
        legend: {
            enabled: false,
            layout: "vertical",
            align: "right",
            verticalAlign: "top",
            y: 55,
            reversed: true,
            itemStyle: {
                color: '#777',
                fontWeight: 'normal',
                fontSize: '12px'
            }
        },
       ...