How to convert base64 string to zpl2 in C# .NET

I'm a C# .NET developer who sends the DHL shipment request to DHL XML-API web service and get the response to print labels, The DHL web services sends the Label (ZPL2) in Base64 encoded string. How to decode this and send this label to a Zebra printer? I couldn't find any references anywhere on how to do this task.

I need to do this in C# .NET