These are the steps I took to install the agent software from http://ocsinventory.sourceforge.net/
All of this is done from a terminal via SSH.
Ubutu Linux - OCSNG_LINUX_AGENT_1.0RC3 Install Notes
Change to root...
sudo su
Switch to /opt...
cd /opt
Download the agent...(I put this on one of my webservers for convenience)
wget http://path-to-agent.gz
Extract Agent...
gzip -cd OCSNG_LINUX_AGENT_1.0RC3.tar.gz | tar xvf -
Install essential compiling tools...
apt-get install build-essential
Install required support software...
apt-get install libcompress-zlib-perl libxml-simple-perl libnet-ip-perl libcrypt-ssleay-perl libwww-perl -y
All set.
Now run the setup
cd OCS*
./setup.sh