costales@dev:~/Desktop$ xmodmap -e "keycode 166 = less"
costales@dev:~/Desktop$ xmodmap -e "keycode 167 = greater"

costales@dev:~/Desktop$ cat ~/.Xmodmap
keycode 166 = less
keycode 167 = greater
costales@dev:~/Desktop$

# Set custom keycodes
#
# This file is sourced by Xsession(5), not executed.
# The "|| true" is to ensure that the Xsession script does not terminate on error

USRMODMAP="$HOME/.Xmodmap"

if [ -x /usr/bin/xmodmap ]; then
        if [ -f "$USRMODMAP" ]; then
                /usr/bin/xmodmap "$USRMODMAP" || true
        fi
fi