First Way – Insert the different SIM card in the modem and plug it into the PC. E353 should ask for an unlock code. Just input the unlock code and click OK to unlock your dongle.
Second Way – Some modems come only locked to their dashboard. This means you can not create any profile inside the connection manager or software of the modem. In that, you need to change the software of the modem, which is also called rebranding. You can download the latest Huawei mobile partner and install it on your PC to enjoy the unlocked dongle.
Third Way – You can use the Huawei Code writer tool to write unlock code in any Huawei modem, including Huawei E353.
Fourth way – It is the worst way. It involves the firmware change in your dongle. In this process, if any interruption will happen in the dongle, then your modem will be permanently dead. It will ask for firmware code (password), which you can generate from the universal master code tool while updating the firmware.