Reclaiming YDL partition for Mac

[The Badger]

While this may see blasphemous. . .

I need to wipe out my YDL installation and reformat the partitions for 
Mac OS X so that I have enough space to get Oracle's 9i R2 Mac Beta on 
this machine.  I'd like to do this in such a way that I do not destroy 
my Mac OS X installation that already exists on the same drive.

How can this be done?  It seems like the Disk Utility for Mac does not 
see the YDL partitions.  Can I do this with fdisk?  Has anyone done 
this successfully?

I also expect there will be a need to modify the boot loader?

Thanks,
	John