This is a demo tutorial. While there is no step-by-step commentary available (yet), the live demo below is fully functional. Feel free to open it for full source code.
Most of the elements on a chart - e.g. series or chart itself - have appear() method. Calling it will re-play whatever animation was played when the chart was first loaded, for example series morphing into place. This demo showcases this functionality.
See the Pen amCharts 4: Trigger a replay of the chart initial animations by amCharts team (@amcharts) on CodePen.