I has also previously seen your second link. I everything I could find most of yesterday, got frustrated and gave up.
This morning, I installed xubuntu and ran: sudo apt-get install firmware-b43-installer. Didn't work (I'm sure I skipped a few steps). I was about to review everything, then tried: the bcm43xx-firmware_1.4-0cafuego1_all.deb That worked.
So, now I'm trying to decide, stay with xubuntu, or retry lubuntu and bcm43xx-firmware_1.4-0cafuego1_all.deb without all the other flailing...