1. Stop the NAS server from the management console
2. Create a new codeunit in the navision client
3. In the run method of the new codeunit instatiate and execute the StartNAS method of the 6810 codeunit with a parameter 'NEP-1' or whatever you have used in your instance of NAS; it should display a message stating that the service has started.
4. That's it the debug mode is now enabled within the navision client now just enable the debugger and start debugging.