change a class inside a dll, in c# asp.net mvc5?

I created a dll file and added a class inside that like what you see here:

     using (CSharpCodeProvider codeProvider = new CSharpCodeProvider())
        {
            System.CodeDom.Compiler.CompilerParameters parameters = new CompilerParameters();
            parameters.GenerateExecutable = false;
            parameters.OutputAssembly = "Per.dll";
            CompilerResults results = codeProvider.CompileAssemblyFromSource(parameters, "public class PersonVM{ " + "public int id{get;set;}" +
              "public string Name{get;set;}" + "public string LName{get;set;}" + "public string LNamee2 { get; set; }" + "public string L4 { get; set; }" + " }");
        }

now whats the standard solution to changing the PersonVM class inside Per.dll? what's your Idea about that?

For describe: i'm using Asp.Net MVC5. and my final purpose is generating my view model classes at run time.

tell me if you have any other solution and ideas