[libvirt] Change of CDROM source via virsh

[Radek Hladik <radek eadresa cz>]

Hi,
	I would like to ask what is the simplest way, how to change ISO mounted 
in VM's drive. I am using libvirt+kvm+qemu and only way I found is via 
virt-manager, but there are some problems with it - it is not working 
properly on some Fedora testing guests and it disables the VNC password 
for the VM. I'll try to look to the sources of virt-manager if I could 
find the cause (I am thinking using dumpxml without SECURE flag) but I 
would like to change the ISO via script (i.e. via virsh). There must be 
some simple way but I can not find it...

Radek