Yeah, I know but a reboot is necessary to install the font if you're gonna copy it to /usr/share/fonts/ OH and it seems that there's a limit to the number of killalls you can do to qtlockscreen, after you exceed that limit, qtlockscreen stops restarting and the ordinary hildon lockscreen comes up.
root start qtlockscreen
fc-cache -fv root /etc/init.d/maemo-launcher force-reload