1. Download Universal Master Code Calculator so that we get the FLASH CODE from this link
2. After downloading it Put the IMEI and get the FLASH code that we are going to use them as a PASSWORD.
3. Download HUAWEI E303 firmware update from this link..
4. Unzip the file and make sure the modem is connected and it has been installed with the SIM card inside it.
5. Quit the dashboard if its open and run the update, wait and when it ask you for the PASSWORD input the FLASH CODE you got from Universal Mastercode Calculator.. Wait for about 3 min and your modem will be unlocked PERMANENTLY.
Plz do in ur own risk