It's probably easy, but I can't figure out how to hide the labels in the pie chart (PieChartView):

I believe it's drawEntryLabelsEnabled and set it to false. 
self.pieChartView.drawSliceTextEnabled = NO;
dataSet.drawValuesEnabled = NO
you have to set dataSet.drawValuesEnabled to false, only setting drawEntryLabelsEnabled to false doesn't work. 
Most helpful comment
self.pieChartView.drawSliceTextEnabled = NO;
dataSet.drawValuesEnabled = NO