After driver installation, make sure module became visible in device manager under Modems, Ports and Network adapters lines (If it doesn't, restart device, if it has removable battery remove it and keep it like this for 10-15 seconds)
Launch DC-Unlocker client
Detect device by selecting SierraWireless modems from manufacturers drop down menu list, then click magnifying glass button
Wait till program detects it
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” button
Wait for device to be unlocked
After unlock, restart device to complete the process