On the cdrom there are two files: minirt24.gz and minirt26.gz
these are the 2 files for two different kernels

I recommend to do this as root.
so:

1.) get root (su)
2.) copy them to a directory on your hard drive
3.) unzip them (e.g. gunzip minirt24.gz)
4.) create a temporary directory (mkdir temp)
5.) mount the extracted file into the temporary directory (mount -o loop minirt24 ./temp)
6.) change the "linuxrc" file in the mounted temp directory with an text-editor
7.) unmount the temp-directory (umount temp)
8.) zip the minirt24 file (gzip -9 minirt24)

thats it. (I apologize for my bad english )