I have read the answers at
C# 6.0 Support in Visual Studio 2012
however it's not clear how to get it done on an offline PC.
I have downloaded the latest stable version of the C# compiler available at
https://www.nuget.org/packages/Microsoft.Net.Compilers/
but I'm clueless of what do I do with the dowloaded nuget package, best I could do was rename it to .zip and extract it but I got stuck again not know how do I reference that in Visual Studio 2012
.
Also I have no idea how to upgrade Nuget
to the latest version (as outlined in that answer) before I do the other steps?