Hi there,
After many tutorials and searching the websites to unlock my w880i CID53 phone - I finally found a way to do it and would like to share!
This method also unlocks CID52 phones by using the SEUS update service to upgrade (also installs the USB drivers for you).
Firstly you must remove your network custom pack by replacing it with a generic custom pack.
Use this tutorial to do so: Flash K800 CID53 with K810 software CID53 (for begginers) - Esato archive
Then you can create a remove lock patch using simox v2.2 (http://www.*******.com/forum/attachm...chgen_v2.2.rar) following this tutorial: Free Unlock Sony Ericsson Phone | SE Flashing
Now to use this you need to install 3 files and then apply the unlock patch using this tutorial: Patching CID53 (DB2020)DB2010,2012 - Top Sony Forums
Note: After you applied/copied the rest and qamaker accross, copy the unlock patch accross at the same too and now you're phone is debranded AND unlocked!
You can get all the firmware files and custom packs from here by registering first and using google translator to find where everything is: http://www.********.cz
Enjoy!