Note: before proceeding with steps below insert operator's sim card that does not work with device. For example if it's locked to operator "A" insert operator's "B" sim

Launch DC-Unlocker client

Detect device by selecting ZTE 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” button

Wait for device to be unlocked

After you see that modem was successfully unlocked, restart it by disconnecting and connecting back. Now you can use it with any SIM card.