Turn off phone, then hold at same time buttons "Vol. -" and "End call" (red button) and then press "Power. Hold all 3 buttons pressed for 5 seconds. Phone should hang on startup. After this connect usb cable.
Download drivers for Windows XP, Windows 7 and Windows 7 64bit
Install Huawei U8150 IDEOS drivers for Windows XP
Install Huawei U8150 IDEOS drivers for Windows 7
Further actions require internet connection and DC-unlocker software
Select Huawei phones, model leave autodetect.
Press detect button (Big magnifying glass)
Valid dongle or user acocunt required for full detect.
Open dc-unlocker server tab and enter your username and password. If DC-Unlocker/Vygis/Rocker/Infinity dongle is connected, do not enter username and password, only click "Check login".
Press check login and you should see your username and credits left.
Select again Huawei phones, model leave autodetect
Press detect button (Big magnifying glass)
Open unlock tab and press unlock.
After you see that phone successfully unlocked, remove battery and restart phone. Now you can use it with any sim card.