Knoppix Hard Disk Install - Upgrades?

[Bryan Richard]

So, my Mother has decided to jump feet first into the world of email and
wants a computer. I've dusted off an old Toshiba Tecra we had lying
around, popped a Knoppix CD in it and everything works find. Actually,
I was a bit surprised at how snappy KDE was. 

It is, however, a bit sluggish when fetching apps off the CD so I am
considering a hard disk install. My question is, how does one upgrade a
Knoppix hard disk install? Does the Debian-like feature of apt-get
upgrade exist?

Thanks, 

- Bryan