How to start single user mode or safe mode

[Stephen Liu]

Hi all folks,

Accidentally I made a mistake

# ee /etc/rc.conf
.....
hostname=localhost
....

and could not start the PC

At booting
......
Enter full pathname of shell or RETURN for /bin/sh:
Hit <ENTER>
# ee  (could not work)

I rebooted the PC.  At booting, selecting [3] or [4] could not boot to 
'safe mode' nor 'single user mode'

Kindly advise how to boot to 'single user mode' or 'safe mode'

TIA

B.R.
Stephen Liu