Launch DC-Unlocker client
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 ".
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 Unlocking tab, click “Unlock” button
Wait for device to be unlocked
It might be so that you get an error during unlock, 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 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.