You should be able to do the BIOS update via USB. You would first need to visit the manufacturers website and download the updated BIOS from there. When you get the file, make sure to take note of the files name. You will need it later.
Once you have it on the USB, connect it to your computer and boot the computer with the USB attached. When the computer is starting up, be sure the press the correct key to enter your BIOS. It is often F2, but not always.
Now you want to enter the boot menu and change the hardware listed under "Primary Boot Device" to the attached USB flash drive. Then select "Save Changes" and then "Exit" to restart the computer.
When it restarts, wait a few moments and you should see the command prompt to appear on the screen. Once the command prompt appears, type in the name of the BIOS update file on your USB flash drive, then press "Enter".
Press the "Y" key to confirm the update.
IMPORTANT NOTE: Do not remove the USB flash drive from your computer at any time during this process.
Once everything is all done, after the BIOS update process has finished, you can then remove the USB flash drive from your computer.
The update program will indicate when the process is complete. Your computer will automatically restart itself with the new BIOS.
NOTE: Remember to go back in and change the boot order back to the way it was before you changed it to load the USB first.