First, you need to download the remix: http://www.ubuntu.com/getubuntu/download-netbook
Installing using a USB key
To install Ubuntu Netbook Remix with a USB key, the easiest way is to follow the instructions here: https://help.ubuntu.com/community/Installation/FromImgFiles
Installing over the network
I configured by DHCP server to netboot the Ubuntu install. This post is a placeholder – I will add more info soon, but here is the gist:
On the DHCP server, I untar’ed http://mirror.internode.on.net/pub/ubuntu/ubuntu/dists/jaunty/main/installer-i386/current/images/netboot/netboot.tar.gz to my tftp server, and then used the PXE netboot option on the agora pro (press F10 when it starts to boot) to boot the installer.
During install, you can choose to install Ubuntu Netbook Remix.