Firmware is software that is loaded onto the hardware components of your router.All firmware updates should be downloaded through the manufacture of your router and saved to your computer. With most network routers the firmware update will end with .bin and should be saved to a place that will be easy to remember, such as your desktop.
After the file has been downloaded open your router setup and locate the firmware upgrade section. The picture shows an example of the Firmware Upgrade section under Administration on a Linksys network router.
Point the firmware upgrade section to the firmware file you downloaded earlier and start the upgrade. As should be mentioned on the firmware upgrade page it is important that the firmware upgrade is not interrupted, interrupting any firmware update will prevent that device from working.