Sierra Wireless AC770s Drivers download
Launch DC-Unlocker client
Detect device by selecting SierraWireless/NETGEAR 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 "
Note: if you can't login or get error connecting to server after connecting Sierra Wireless AC770s to PC, check these settings here
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