Running conversion/migration tool where donor root/SSH access isnt available

Is it possible to run this conversion tool having forgotten the root password for the donor machine?

possibly from the GUI Asterisk CLI

And if not, being that the virtual machines are all on cyberlynk, is it possible to connect through VNC and reboot in single user mode to reset the linux root password?

No it has to run from SSH. Sorry

Yes google linux single user mode to reset the password.