Resolution Isuues

[JUSTIN QUINLAN]

Hello I jsut installed my first copy of FreeBSD and I decided to use GNOME. When I rewrote /etc/rc.conf to include gdm_enable="YES"  When I restarted FBSD it booted normally until it got to the login screen and my monitor went black and flashed a warning saying my resolution wasn't correct and to change it. But I can't get into ee to edit /etc/rc.conf. How do I change back to default login? Thanks for your time Juncey