!! Each point is there for a reason, don't miss anything! Before you start playing, read everything and make sure all is clear to you! If oyu have any questions, look for answers of other users before you ask.
Make sure there is no problem with driver on your PC. If you're unsure about something do not take the risk.
1. Make sure phone is charged in at least 50%, remove back cover for whole process (so you won't have to do it 5 times).
2. Make a backup of QPST (only for 4th paragraph)
3. Extract dump 2.3.6 and DFU tools into a separate folder. Enter phone into DFU-mode: take battery out and in, press and hole '+' and '-' buttons, put USB cable in, press POWER button while holding
'+' and '-' keys, at this stage you have to get ZTE Handset Diagnostic Interface (DFU) (COMx). (If phone is seen as unknown device on computer, install driver from ZTE package)
4. Start DFU Tools, on the right side put the path to dump 2.3.6, on the left select all boxes. Check box on the right is selected. Click the left button as the bottom and wait for completion.
On success phone will go into FTM-mode. It is very important to mark right boxes
5. Close DFU tools, after phone reboot Chinese firmware will load, you can change language in settings to english (gray letter A in settings).
6. Download the modified Russian 2.3.6 firmware
7. Switch on debugging mode on the phone, and connect to Pc, download CWM, run recovery 220.127.116.11.exe, keep pressing enter until window closes.
Switch the phone off, switch it back on holding (don't get which keys) to put phone into recovery mode (Chinese one
a) In chinese characters select menu item 5, in the menu you will see four options - first two are choice of firmware files and last two need to be adjustes since you will need to disable signature verification for firmawre and scirpt.
Press - and see which character appeared (probably a chinese one), open the menu below - and get the same character appear.
Next, in the first two rows seleft firmware file from step 6 and acknoledge, wait untill progress bar is completed and three charactes will appear.
Reboot via CWM or by removing batter. (If flash does not work, than last two rows were selected in opposite meaning)
8. Next select update.zip to install after reboot to root, in settings select Update and update to 4.0.4
9. (Sorry I don't get this one) orig: .S QPST help restore previously removed backup radio module tab Restore (checkbox is not selected.)