If you want to change a specific option setting and keep the rest untouched, you can get the options beforehand and update the "step" value only:
categoryAxis = chart.options.categoryAxis;
categoryAxis.labels.step = 1;
takes the current configuration of the category axis and updates the step from 3 to 1.
Can you have a look at the sample and inform me if this is what you want to achieve?
Get quickly onboarded and successful
with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.