You just have to follow these easy steps:
1. Download and Install Universal Master Code.
2. Connect your data card with other then default SIM and enter the IMEI of that data card in the box provided (check backside of your dongle for IMEI)
3. Click on the calculate button, then it will show you unblock code and flash code, copy both codes in safe place.
4. Then download Huwaei 173 Firware Update.
5. Install the downloaded firmware to update device firmware. Then you will promoted for unblock and flash code enter those codes which one we copied before.
6. Now you need to download Huwaei Dashboard.
7. Install the Huwaei Mobile Partner and create a new Internet profile into it.
That's it, now your dongle is unlocked.
Note: It will only supports following Data Cards:
Airtel 3G Data Card
Vodafone 3G Data Card
Huawei 3G Data Card (E 173, E 1731, E1732, E 175, E153)
MTNL 3G Data Card
MTS 3G Data Card
BSNL 3G Data Card
Reliance 3G Data Card
Beetel 3G Data Card
Tata Docomo 3G Data Card