Modify Leopard iso with Linux

My box contains only SATA disks and to test Leopard 10.5.1, I need to replace the kext file.

I can mount the iso using hfsplus filesystem (mount -o loop -t hfsplus Leopard.iso directory) and I get all thoses directories/files in my directorty :

Applications Desktop DB Desktop DF Install Mac OS X.app Instructions Library Optional Installs System Volumes bin dev etc mach_kernel private sbin tmp usr var

I can copy the directory and change the kext.

If I simply mount the iso (mount -o loop Leopard.iso directory), I get :

boot boot.cat boot0 boot1h boot1u boothelp.txt cdboot chain0 i386boot.iso startupf

Seems to be all needed boot files.

Is there any way to do a bootable CD with mkisofs and those files ? I try the following command without success :

mkisofs -r -b src3/boot.cat -c src3/startupf -o leocustom.iso MountedISO/

Any clue ?

I haven't any windows or mac computer..

Thanx,

iero.