Get the service manual.

Yeah, check minuszerodegrees or Google for the service manual.

I have a 460CDT and the hard drive just slides right out of the front when you take off just one screw - maybe yours is different?

Remove the nuts on both side from every port on the backside. That plate is held in place there.
I don't know sure, but with the later versions you had to remove the whole screen first, don't know if that is needed here and that it is one piece with the topcover from the notebook.

From my general experience with laptops:
- carefully remove the plastic stripe just above the keyboard
- you will now be able to remove the keyboard
- under the keyboard there should be more screws holding the case together

Advent-nurse wrote:

And something else: this thing has a total of four CardBus slots, an infrared sensor, an external floppy slot and a USB port, besides the serial ports. How standard was this and what was the IR sensor used for?

The old Toshiba's are built proof, I keep collecting these without even trying, everyone had one and they never die. Shame I cant think what to use them for.
I'm no expert but 2 cardbus slots were common even in early P4 laptops, so can imagine earlier laptops having 4.
Toshiba laptops FDD's also used to have a habit of multiplying by themselves, I threw out a load few years ago, regret doing that now, as the port did change somewhere along the line.
Infrared was very common in laptops, was meant to be a way to transfer files, especially with other mobile devices from the era like phones or PDA's.
Wifi and Bluetooth killed it off