Last things first... I think your post is formatted perfectly!
I don't actually back files up. You can call that lazy or call it having 3 internal laptop drives, 1 external drive and another laptop to boot (pardon the pun).
What I do like to do is leave myself an easy way of reverting something I've changed by not actually changing lines but rather commenting them, copying them, inserting them and changing the cloned line. This makes it easy to reverse bad mistakes.
Hypothetically type this command:
` cat /usr/share/X11/xorg.conf.d/50-nvidia-drm-outputclass.conf/nvidia-drm-outputclass.conf.
And the output is:
# This xorg.conf.d configuration snippet configures the X server to
# automatically load the nvidia X driver when it detects a device driven by the
# nvidia-drm.ko kernel module. Please note that this only works on Linux kernels
# version 3.9 or higher with CONFIG_DRM enabled, and only if the nvidia-drm.ko
# kernel module is loaded before the X server is started.
Let's say I read a blog / answer / comment that said to change MatchDriver to "nvidia-quacamolie" I would instead do this:
# MatchDriver "nvidia-drm"
# As per www.thatguysblog.com/nvdia_trial_and_error_1001 set quacamolie
If something goes wrong, I edit the file again, leave a comment on what went wrong, restore the original command by removing the '#' and then comment out the new command by inserting # in front. You could say my lazy backup method means the backup is in the configuration file itself and is more of a "way-back-out" than a "backup".
That takes care of changing configuration files.
If on the other hand you
sudo apt-get install nvidia-367 and you were currently on
nvidia-304 and things turned sour then you would simply purge
nvidia-367 and install
nvidia-304. Which according to Nvidia web site I should do on my own platform with Nvidia GeForce GT650M. But because I'm lazy I just turn off Nvidia and turn on Intel.
Which reminds me most people just use the Intel Graphcis driver (i915) and don't bother turning on the Nvidia. You have Intel HD3000 graphics and I have HD4000 graphics which has great performance. Even on my old Toshiba (year 2007) laptop with HD2000 graphics Ubuntu 14.04 with Unity 3-D graphics was acceptable and processor barely hit 50% usage with Video running on external TV and 10 chrome windows open on primary (built-in) display.
This isn't exactly the answer you were looking for but I hope it helps.