Newbie Question: is there a rescue mode or shell access from loader?

[Mick mtn]

FreeBSD 11.0R p2
on a macbook pro,

System was working, added some drivers to loader.conf, now system panics
and reboots after 15 seconds.  one of the errors I can see relates to
module vesa can not register 17
vesa.ko already loaded

I can escape too the loader prompt.
But do not see how to edit files from the loader prompt.
Can anyone help me get to the shell?