How to define Endpoints for multiple service contracts(interfaces) implemented in separate classes ?

Hi
I have taken a WCFService library in which I have defined multipled service contracts(interfaces) in separate cs files and implemented them separately. For example ..
[ServiceContract]
public interface IService1
{
 [OperationContract]
  string GetService1Msg();
}
[ServiceContract]
public interface IService2
{
 [OperationContract]
 string GetService2Msg();
}
I have defined above interfaces in separate cs files.
Now I have implemented them separately as follows.

//this is Service1.cs file
public class Service1 : IService1
{
  string GetService1Msg()
  { 
     retutn "Service1";
  }
}
//this is Service2.cs file
public class Service2 : IService2
{
  string GetService2Msg()
  { 
     retutn "Service2";
  }
}
My intention here is to expose above two as two service contracts/interfaces outside.
Now My question is how to define endpoints for these two service interfaces in app.config of this WCF Servicelibrary?
Thanks in advance
Padma