Before I start with the tutorial, take a look at the pics below, those are the ones I tried on my phone (6600 firmware v5). It also installs nicely on frimware v3 & v4.
WARNING: You will lose your default font when you follow the steps below. SO please make necessary backup should something go wrong.
Also prior to installing this fonts, I suggest you install FExplorer on your phone. Ok so here goes...
Step 1. Download the fonts HERE.
Step 2. In the Zip file you will see
Step 3. Then send the FontRemover.sis to your phone and install it. Once installed, launch the application and it should ask you if you want to delete font. Click on Yes and it should tell you to reboot your phone. Do NOT reboot first.
Step 4. Now send one of the font sis files, lets say modern.sis to your phone and install it to your C drive (your phone, NOT mmc). Once installed then reboot your phone.
Step 5. When it starts, you should see the default fonts replaced by the ones you have just installed.
Now I cant stress this more but you need to understand that you can only use ONE FONT at one time. If you want to use another font, you will have to go back to step 3 & 4.
As for the .gdr files, you will need to do it this way.
Step 1. Use FontRemover to remove the fonts.
Step 2. Open FExplorer and goto C:\system and create a "fonts" folder as shown below.
Step 3. Send the .gdr file to your phone. Do not open it as it will say unknown file format.
Step 4. Find the file in your mail folders (C or E:\system\mail\00001001_S\0-9, a-f) using FExplorer.
Step 5. Copy or Cut the file and then paste it to the C:\system\fonts folder.
Step 6. Exit FExplorer and then reboot you phone.
So its that simple. In my testing, I found that some fonts like tahoma & mssans does not make much different (well atleast to me) as the modern font did. I've only managed to try on one 7610 with firmware v4.0424.ch and I only see small changes, not like it did on a 6600. So you guys with the 7610 might be a little disappointed about this.
Anyway, Good luck!
Please ignore the warning about you might lose your default font after following the steps. Your original font is stored in your Z:\system\font folder, so if you decide to remove the font you have installed with font remover or by deleting d C:\system\fonts folder, its totally safe.
Easy GDR Creator attached. You can also download it HERE,