Download the LinqToXsdCore global dotnet tool:
dotnet tool install -g LinqToXsdCore
To generate the CDS-XML_Message_Root-V6-2-3.xsd.config file:
linqtoxsd config -e CDS-XML_Message_Root-V6-2-3.xsd
To generate the C# source code (using the .config file):
linqtoxsd gen -a CDS-XML_Message_Root-V6-2-3.xsd
Then debug the tests in the XsdParsingTests, there's example code that will allow you see how the LinqToXsd library works.