Removing highcharts.com credits link
You can customise the credits, changing the URL, text, Position etc. All the info is documented here: http://api.highcharts.com/highcharts/credits. To simply disable them altogether, use:
credits: { enabled: false},
It's said here that you should be able to add the following to your chart config:
credits: { enabled: false },that will remove the "Highcharts.com" text from the bottom of the chart.
add
credits: { enabled: false}[NOTE] that it is in the same line withxAxis: {} and yAxis: {}