If you are talking about the font stored in the actual tileset graphics, you will need something like the phoebus tileset merge utility, or paint.net (or GIMP on linux, or something equivalent for OSX)to manually replace them in the tileset files. Those are also located in Data\art.
I'm talking about right that. What is Phoebus merge utility? Could you give a link or something? I've really tried googling but didn't find it(
I took a bit a time to look around, and here is what I found out:
The Phoebus tileset utility is included with his tileset download. Check the mediafire link on that forum post here:
http://www.bay12forums.com/smf/index.php?topic=137096.0However, I'm not positive how it works yet, and it may be more difficult to get what you want (Spacefox with something else for a font) out of it than it would to just change it yourself.
Here is what I suggest:
For Windows:
download both tilesets, and extract them somewhere. Doesn't matter where, we are going to delete them afterwards.
Open both tileset files in an image editing program that supports saving in a PNG file. I suggest Paint.net (
http://www.getpaint.net/). The tilesets are in the following locations:
-Phoebus: Extracted Directory\data\art\Phoebus_16x16.png
-Spacefox: Extracted Directory\data\art\Spacefox_16x16.png
Once both are open, compare the two. You will notice that the font is part of this file. You will need to copy the items you want from one tileset to the other, and then save it as a PNG file. Note that the spacing is VERY IMPORTANT, as dwarf fortress takes the tileset file and breaks it up internally into 16x16 pixel chunks.
Unfortunately, it isn't as easy as the directions might indicate... and there isn't an easy way for me to describe what you need to do. I'll see if I can make the appropriate files for you, but no promises. I encourage you to dive in and take a look for yourself!
Optimally, you will copy just the letters from another tileset, into the spacefox one. Then, you will save your Franken-Tileset over top of your tileset in your 'Active' Dwarf Fortress game. Make a Backup first!! It will be in your data\art directory again.
Good luck!