Lexmark C3426
Using the notification center
This method is applicable only in some printer models.
From the control panel, navigate to the notification center, and then select Firmware update available.
Select Install now.
The printer reboots automatically after the update.
Using the Settings menu
From the control panel, navigate to Settings > Device > Update Firmware.
Depending on your printer model, select Check for updates or Check for updates now.
If a new update is available, then select Install now.
Use the features of the control panel to navigate easily through the printer functions and settings.
How to Update Print Server Firmware Using the Web Interface