First, have a nandroid in case something goes wrong.
If you're using a PC I would look at FrHead which you can get here at
sourcefourge you can also just do a google search for one if you don't like this one. Don't pay for one though, most are free and do all that you will need. If you're like me and use a mac I use
hexedit. Here's how to go about editing the framework-res.apk
1. extract framework-res.apk from the theme you're using or straight from system/framework/framework-res.apk. Put this file on your computer for editing.
2. rename it to framework-res.zip
3. Unzip the folder. I'm not sure how PC's unzip stuff, my mac saves the original .zip file. You will need the original .zip later so make a copy if PC's do it differently.
4. with the file open navigate to res/xml/eri.xml and right-click and open it with Frhed or whichever hex editor you choose.
5. My hex editor looks like my picture below. Look for the text eriinfo......64.....verizon wireless. Highlight over the corresponding bits and edit it to whatever you want 16 characters maximum and if you only use 8 characters you need to input 8 spaces. HAS to be 16. save the .xml
6. rename framework-res.zip back to
7. Open the original .zip with 7zip or something equivalent.
8. navigate to res/xml and drag the new eri.xml into here and overwrite the original.
9. Save this new theme.zip
10. rename to .apk.
11. I usually then open the theme I'm using in 7zip and replace the framework-res.apk that's in there and reflash the theme. I would imagine that you can also just put it there manually. Make sure you set the permissions to rw-r--r-- then reboot. Not totally sure about the second method but don't see why it wouldn't work.
If it doesn't work you can always upload the framework-res.apk and I'll edit it for you.