ZFS Mounting ZFS Block device || Resetting VM password

Hello everyone,

I am using FreeBSD as a host system and as a guest inside a bhyve-VM. Unfortunately I do no longer have access to the root password of the guest. (Wrote it on a piece of paper and left it in a different country. Due to Corona I cannot go there atm.) The virtual machine is based on the freebsd-zvol.conf template so I use one of these 'sparse-zvols's. Mounting it directly does not seems to work. Neither does mounting via the /dev/zvol/.../disk0.
My plan is to mount the device in /mnt and then chroot into it to change the password.
I also tried setting the volmode to geom (default is dev) but it doesnt seem to change much.

Does anyone have an idea on how to approach this?
Thank you for your reply.

In case someone else finds this thread in the future: Put loader_timeout="20" into your virtual machine's conf file.