How do I flash an unbranded rom on my Lumia 635?

[Windows Central Question]

Lumia 635 Unbranded ROM

Hey,

I bought O2 Lumia 635, but I want to flash an unbranded ROM so I can get the latest updates.
Do I need to get the SIM unlocked first?
How can I flash the new ROM?

Thank you

 

[xandros9]

I don't know the flash procedure, although there are others that do.

However, you do not need the SIM to be unlocked. I used a guide on here to flash my 920 to the unbranded French ROM about 1 3/4 years ago but its still SIM locked.

 

[EBUK]

Re: Lumia 635 Unbranded ROM

First off, take a look at this tutorial on XDA:
[Tutorial] Flash/unbrand Lumia devices - Post #0 - XDA Forums

I followed it, and flashed my spare L735 from EE with the CV ROM.

To find the correct product code (needed to download the correct ROM) I used this thread:
Nokia Product Code Listing for NaviFirm+ Download - (Nokia 730, 735, 830 Added) - GSM-Forum