I would like to know how to add a new language option on my V600i. I'm not at all bothered about unlocking or debranding. I have managed to download what I think is a language file and dictionary file from a website but have no idea what software to use to upload them to the phone. I guess there is also a customisation file in there somewhere to let the phone know that there is a new language available. I've never flashed firmware on a phone before but have done dvd players / satellite boxes / computer bios etc before so not a complete beginner. Any help would be appreciated. Thanks. SB.

Tutorial

Thanks for the link. I've been doing a bit of a read around various forums and have started to make progress but not entirely successful yet. I'll describe what I'm doing to help other users.= who may be attempting the same thing.
Firstly drivers and USB connections - I needed to remove the battery and sim and cable, wait 10s and insert the battery, add the cable and connect phone via USB. I needed to hold C and click the on button. (No one else seems to mention the on button!)
I've downloaded tools such as XS++ and Far with a jdflasher plug in. My phone is a UK Vodafone V600i. I don't need to unlock or debrand but just want to add Polish language to the menus.
I managed to explore the phones file system with both FAR and XS++ and have downloaded the Polish language files for the K600 from a Russian Website.
I found that the tools I have will not allow me to copy off "Allowed Languages.txt" and "customize.xml" files to read and edit on the computer. I'm reluctant to replace them with generic files in case I mess things up. I only appear to be able to upload files to the phone and not download from it. FAR Manager will not let me copy files using F5 - I get an error message which disappears instantly.
I decided to have a play yesterday and renamed my "PL" language files as "HU" or something else that I didn't use but was already registered in the firmware. Then uploaded using XS++. Partial success. Everything worked except the phone tripped out when I wanted to write a text message. (As a side note, the language files from a K810 or similar went on first and didn't work so I went and found the K600 ones instead)
In parallel I wanted to try and backup or download the firmware from the phone. The GDFS feature in XS++ would not do this. Error messages again.
Also when connecting using XS++ it connects but I get error messages and it does not identify the phone details correctly.
Help or advice as to what to do next will be appreciated.

Can you post an XS++ log?

Started from scratch and did a lot more reading as I should have done in the beginning.

Look at the unlocking thread:
http://forums.se-nse.net/index.php?showtopic=36780

Use >*<<*<* to read the firmware type on the phone. In my case R2BB001.

Use XS++ to identify the phone type - in my case RED 49

Now go and download the MAIN and FS firmware and possibly a custom pack.
http://www.seusers.com/forum/local_links.php?catid=59

I chose a FS with Polish and English - my chosen languages.

Use XS++ to upload the firmwares and there you have it.
Lost the Vodafone branding but not that bothered.

Phone can be unlocked by following advice in link above and using the MAIN firmwave file to generate a patch.

Thanks.

SB

So you sorted your problem ?