Well, done it now anyway. Dead easy, for anyone who's interested:
Lift the keyboard up from the top edge. There are metal clips above'Ins' 'F12' 'F8' 'F5' and 'ESC'
Once the top edge is free (You may need to lift it a little higher to free off the double-sided sticky tape that fixes it to the plate below) then all you need do is slide it back (towards the monitor screen) and it'll lift out.
Unplug the flexi-track connector and you're done.
Graham,
May 2007