Yes, you can.
Please refer
https://www.mobileread.com/forums/sho...d.php?t=141388
to make your kobo as an ftp server.
The kobo fonts file were located in ./usr/local/Tolltech/QTEmbedded-4.6.2-arm/lib/fonts
The kobo's Menu font is georgia(including georgia.ttf, georgiab.ttf, georgiai.ttf and georgiaz.ttf, they are Normal, Bold, Italic and BoldItalic form of georgia).
What you should do is to put your favorite font into this directory to instead georgia.ttf.(Note: Befor you do this you must change your font's
filename and the
meta data as same as georgia.ttf) .
I think you will need a font tool to do this.