Note: before proceeding with steps below, set adapter bindings by following instructions here. Also insert operators sim card that does not work with device. For example if it's locked to operator "A" insert operator's "B" sim. Connect device to PC using USB cable
Launch DC-Unlocker client
Detect device by selecting Huawei modems from manufacturers drop down menu list, leave Select model as auto detect (recommended) then click magnifying glass button
Wait till program detects device
Open Server tab, enter your username and password that you received after credits purchase. Click "Check login". (you can buy credits here www.dc-unlocker.com/buy).
If DC-Unlocker/Vygis/Rocker/Infinity dongle is connected, only click " Check login "
Open Unlocking tab, click “Unlock” or "Do Job" button, do not select any option, leave one that is selected for you by default
Wait for device to be unlocked
It might be so that you get an error during unlock (do not disconnect or turn off the device), in this case open Device Manager and locate your modem under "Other devices" line. Right click on one of the lines and select "Update Driver", apply drivers. Do this for other line as well, then repeat detect and unlock procedure. Drivers download here
After you see that modem was successfully unlocked, restart it by disconnecting and connecting back. Now you can use it with any SIM card.