You can access the FW update here: http://tachosafe.ro/rduadmin/updateterminals if you are a manager.
- If the Terminal is online
or online but in roaming 
Check if the terminal is really online with the button in the first row.
Update the terminal with the latest FW available online.
Note: In rare cases it can happen that the FW update is not successful and the terminal remain in Bootloader mod and won't come online any more
When the Firmware update was uploaded to the RDU successful you should see the following message:
After one minute you should check if the RDU FW update was updated. Click on the View Log button next to the message field. You should see in the log a message similar to this message:
If the terminal did connect to the server after the FW update and the FW hasn't changed you should try again 3-5 times more. If you can't update the FW OTA then you have to try to update the FW over USB