Standing in front of the GP30:

Press I/F
Arrow to LAN(ET)
Press OK
Press password
press [C]

Press TCP/IP
The first thing highlighted is - 1. Enable/Disable
Press OK
Pick a frame type from the following chooses
1.Disable
2.Ethernet_II
3.Ether_snap
If you are not sure which to choose ask the admin what they are using(it will most likely be Ethernet_II)
Press OK

Press Clear
Down arrow to IP Addr Mode
Press OK
Choose from the following
1. Manual set (recommended)
2. BootP
3. RARP
Press OK
Press Clear

Assuming you chose Manual set...

Down arrow to IP address
Press OK
IP address is Highlighted, Press OK
Use the arrow keys to get the frist value.
Press OK
Repeat last step for the next three values.
when done press [C]

Arrow to Subnet Mask
Press OK
Use the same process you used for the IP address to set the subnet mask.
Press [C] when done.

Arrow to Gateway
Press OK
Use the same process you used for the IP address to set the gateway address.
Press [C] when done.

Arrow to Broadcast
Press OK
Use the same process you used for the IP address to set the Broadcast address(last octet probably 255).
Press [C] when done.

Press [C] again and down arrow to Application
Press OK
Choose from the following
1. No Print app
2. LPD (Recommended)
3. LPS (Japan Only, I think)
Press OK
Press [C]
Press END

You are ready to party, have fun.