How do I update from 8.10 desktop to 9.04 from the command line?

I have an offsite Ubuntu 8.10 Intrepid desktop that I would like to update to 9.04 Jaunty. I have VNC access, but from previous 9.04 upgrades, I have noticed that vino goes inactive near the end of the install, and I fear losing visual control of the machine. Since ssh/screen would be a more dependable connection method, I would like to run the update from the command line. It appears update-manager is a GUI-only program, however.

Question: Is there a procedure for updating Ubuntu 8.10 Intrepid desktop to 9.04 Jaunty from the console command line?