[Libguestfs] virt-sysprep as a Bash script

Hello, Due to some complications, I couldn't run virt-sysprep on VMDK exported from vDirector, the issue has to do with read only disk image and write protection(there is a mention of a lock being held). I gave up afterwards, and I'm looking for a Bash script that does the 'prep' part after the VM is created. I don't mind doing it manually from the console, as I already have to configure networking. I was looking at libugestfs source in github trying to find the steps to effectively do what virt-sysprep is doing. But it's not clear where it's. regards,