You need a bootable floppy with the systemfiles on it. (Format command, L: fastfilesystem etc.) You need hdtoolbox, or hdinsttools. Watch out for the version numbers, because some of this utils from a version working only above KS2.0. Anyway hdtoolbox has a version which correctly working under 1.3 .
Then you need to set some variables in hdtoolbox's icon tooltype. Mainly you need to change scsi.device to your controllers driver. And save. (if you don't now the name correctly you can search for it with scout or sysinfo 3.24)
And search for a device.
Then if you set corretly everything, you will see your hd in hdtoolbox. You can partition it and after a reboot you can format it.