Ok here you go, a step by step guide to de-branding your W810i
1. Go to DaVinvis website and order a log account (This allows you to download the firmware from their servers). Log account can be ordered from here:
http://www.davinciteam.com/index.php?page=buylogs
2. Your login details will be emailed to you.
3. Download the flash client (version 15.94) from here:
http://www.davinciteam.com/client-1594.zip
4. Extract the zip into a folder on your desktop. Enter this folder and run Launcer.exe
5. Enter your username and password which was emailed to you in the relevent boxes top left. Click Info and ensure the credits number is at least "1".
6. Top right of the dialog - under port settings. Click the top drop down box and change it so it says DCU60
7. Click the bottom drop down box and change it to "921600".
8. Plug your supplied USB cable into your PC (dont plug phone in yet)
9. Bottom right of dialog, click Read CID/Test Cable
10. Make sure your phone is turned off, hold the "C" button on your phone and plug in the USB cable.
11. If presented with a windows box saying new hardware found, install the hardware. Drivers can be obtained from here:
http://www.davinciteam.com/USBFlash.zip
12. Repeat step 9 - 10 if nessacary.
13. Note the CID number shown in the box (mine is CID 49)
14. Click get flash files - choose the correct file. Each section is headed with the firmware CID number. Choose the firmware which has EU2 next to it. Click this firmware on the list.
15. Check both checboxs at bottom of dialoge.
16. Click get file - wait for download
17. Check all 3 boxs on the main dialog on the right (next to Main, FS and CDA - Finalization)
18. If needed click the ... next to FS and Main to select the correct files (Will look like this W810_R4CK003_MAIN_EU-EMEA-US - this is for the main box, W810_R4CK003_FS_EUROPE_2 is for the FS box.
19. Change the CDA to CDA102337/10 - Europe2
20. !!!!UNCHECK!!!! "Increase SMS Inbox Volume" <<< This is very important!!!
21. Click flash - hold "C" on phone and plug in lead.
22. Phone will reflash .... done!
Courtesy of another forum that i use, they made a sticky for the instructions
EDIT: The firmware file i used to de-brand my t-mobile branded W810i is
R4ck0003 file EU2 firmware file.
That firmware file also resolve the flashing light problem.
Not a very hard process to do if you follow the instructions
Disclaimer: I will not take any responsibilty of this damaging your phone, i used these same instructions myself and it flashed without any probs. If your unsure of doing it yourself then i seriously suggest you dont try it as i wont take any blame for you messing up your phone.