The Xperia X10 unlock instructions
  1. Verify android version compatibility
    • Supported Android OS versions: from v2.0 to v2.2
    • v1.6 and v2.3 are not supported. If needed, perform the upgrade/downgrade by flashing with compatible firmware (preferably with Android OS v2.1)
  2. Prepare phone & drivers
    • Remove SIM-card and SD card from phone
    • Power on phone, enable "usb debugging" in the phone menu -> settings -> applications -> development
    • Connect the phone and install appropriate adb drivers (you can find them in the Omnius for SE installation folder)
    • Install UsbFlash drivers (connect a powered-off phone while holding 'back' button)
    • Make sure the battery is at least 50% charged
  3. Fill application settings - fill in username/password in server settings in Omnius
  4. Unlock procedure
    • Select phone model (X10)
    • Click Unlock -> Unlock network lock by certificate replacement
    • Connect the phone (power it off and connect while holding 'back' button)
    • When asked, disconnect the phone, remove and install battery, power on the phone, connect the cable to it
    • The procedure finishes, phone is unlocked

If anything goes wrong post the full log from your main Omnius window in support forum. Application creates the TA backup automatically so you can restore the phone by Restore TA operation.

Do not disconnect the cable from the phone and/or manipulate with the battery during the unlock procedure unless you are asked to do so. You might brick your phone.