HP5890 SeriesII Parts and Installation

I've recently come into possession of a few old HP 5890 SeriesII GCs. The problem is they're missing various parts, so I'm hoping someone will be able to help me. I've managed to get hold of a copy of Chemstation E.02.02 which I believe is compatible with this GC (please correct me if I'm wrong). The problem is, this software is seemingly only for GCs with Ethernet connections. From what I've found online it is possible to connect the HP5890's using Ethernet connections, but I've no idea how. Can someone tell me how to get it from the RS232/GPIB rear panel connector (P/N 19257-60020) to an Ethernet cable? Part numbers would be particularly useful if you know them.

Thanks!