How to Reset the 4G Cellular Router USR-G808?


【What is the product model?】: Industrial 4G Cellular Router USR-G808
I have made a script and I reconfigured wrong and selected the device to reboot after 1 minute, but the devices uses something like 1:30 minute to full start, So I can't change my settings. 
How could I make the factory reset?
I have tried a lot of reset buttons combinations.. could you help?
The device keeps restarting after 1 minute so I can't change the configuration I made...



1. The factory parameter settings can be restored through the webpage. Click the button to restore the factory settings. This function is consistent with the hardware's Reload button function.

2, the use of Reload button

  Press and hold for more than 5s and then release, the router will restore the factory parameters and restart automatically.


  At the moment when the restart takes effect, the SIM and 2 lights of the SIM card 2, the 4 LAN and WAN ports are lit for 1 second, and then turned off.