Cecil.cs

var assembly = AssemblyDefinition.ReadAssembly("Cecil.exe");
			var module = assembly.MainModule;
			var type = module.GetType("Cecil.Program");
			
			foreach (var field in type.Fields.Where(f => f.IsPublic && f.CustomAttributes.Any(a => a.AttributeType.Name == "ToPropertyAttribute")).ToArray())
			{
				var newField = new FieldDefinition("_" + field.Name, FieldAttributes.Private, field.FieldType);
				newField.InitialValue = field.InitialValue;
				var newProperty = new PropertyDefinition(field.Name + "X", PropertyAttributes.None, field.FieldType);
				newProperty.HasThis = true;
				newProperty.SetMethod = new MethodDefinition("set_" + field.Name, MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.SpecialName, module.Import(typeof(void)));
				var par = new ParameterDefinition("value", ParameterAttributes.None, field.FieldType);
				newProperty.SetMethod.SemanticsAttributes |= MethodSemanticsAttributes.Setter;
				newProperty.SetMethod.Parameters.Add(par);
				var processor = newProperty.SetMethod.Body.GetILProcessor();
				processor.Emit(OpCodes.Ldarg_0);
				processor.Emit(OpCodes.Ldarg, par);
				processor.Emit(OpCodes.Stfld, newField);
				processor.Emit(OpCodes.Ret);
				type.Fields.Remove(field);
				type.Fields.Add(newField);
				type.Methods.Add(newProperty.SetMethod);
				type.Properties.Add(newProperty);
			}
			assembly.Write("Cecil2.exe");