but you've got to have the new fonts installed.
(i am assuming you have got ROOTSH installed and you've enabled root access in filebox)
i use filebox and copy the new font into /home/opt/user/share/fonts click on the fonts folder as in image below and put all your new fonts in there with the rest of them then reboot.
if you check in notebook your new fonts will be installed try them out as it has been noted earlier in thread that not all fonts look right, open theme customizer and change the font all your added ones will be in there, also if the font looks wrong badly spaced/placed try altering the size of the font hope this helps.

edit: i have only used .ttf fonts