Comment 25 for bug 591886

FAYC: you don't need to open synaptic.

Open up a terminal/shell and run the following command (I'll try to spell it right this time):

sudo dpkg -i --force-overwrite /var/cache/apt/archives/linux-firmware_1.34.1_all.deb

You may need to check which version of "linux-firmware_1.34.1_all.deb" it is with something like:

ls /var/cache/apt/archives/linux-firmware*.dev