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 with 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 DC-Unlocker fully detects modem

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 "

Note: if you can't login or get error connecting to server after connecting Huawei E5878 to PC, check these settings here

Open Unlocking tab, click “Do job” (Do not change any settings if there are more options below "Do job" button)

Wait till you see a message that device was unlocked

After you see that device was successfully unlocked, restart it. Set correct APN address (provided by operator of sim card), then you can use it.