I have guided you in various article that Modem can be unlocked in three ways. In same manner Huawei E353 modems can also be unlocked using three ways, as another Huawei dongle can also be unlocked.
First Way – is just insert the different sim another than default in your modem and then plug your modem to PC. Modem should ask password. Just provide the unlock code here and your modem will be unlocked forever and now you can use your sim in anywhere in the world.
Second Way – Some modems comes with locked to its dashboard. Means you can not create any profile inside the dashboard / connection manager / software of the modem. So you can do here is just download unbranded Huawei Mobile Partner latest version. Uninstall old software of modem and install the latest Huawei Mobile Partner software which download link is provided at the end of the article. Now change the sim and connect your modem with PC and now modem should ask password / NCK code. Just provide the NCK code / Unlock Code in your modem and your modem will be permanently unlocked.
Third Way – You can use Huawei Code writer tool to write unlock code in your any huawei modem including Huawei E353.
Fourth way – It is worst way. In this process if any interruption will be then your modem will be permanently dead. In this process you need to flash the modem with compatible firmware. While flashing the modem just provided the flash code in your firmware software upgration process. After flashing the modem, when you will change the sim, your modem will ask for password / unlock code. Here, just provide the unlock code as password and modem will be unlocked forever.
Users who have un-customised Huawei E353 firmware modem can unlock through either first way or second way. After successfully unlock your modem you should not forget to me.