Problem on Broadcomm Wireless on Debian

Many time, installing debian on many lappy. always stuck on broadcomm wireless.
here is a litle hacking from http://forums.debian.net/viewtopic.php?f=30&t=78407
i fix a little bit :D

first thing to understand, i am not a sudo user, so if you working with pc with sudo command for super user access. just place sudo before command.

get git
#apt install git

download firmware, not only broadcomm i see
#git clone http://git.kernel.org/pub/scm/linux/kernel/git/dwmw2/linux-firmware.git
you will get folder linux-firmware

copy brcm folder

#cp -a linux-firmware/brcm /lib/firmware/

Then try wifi 

#reboot

on my lappy its work well till i post this one.

Debian 9