NET+OS V6 without Ethernet

I wonder if anyone has successfully removed the Ethernet drivers from the NET+OS V6 build. If so is it possible that you could post a small description on how to do it, or just some hints about where the pitfalls. I still need the TCP/IP stack for PPP connections.

The PPP stack can’t be decoupled from the TCPIP stack as it is part of it and the TCPIP stack library includes the PPP stack as well.

Yes, I know that TCP/IP is needed for PPP and it was partly what I wanted to say with “I still need TCP/IP for PPP”! What I need is Ethernet interface and driver removed, without removing TCP/IP and PPP.