Oh my goodness! What has science done!
Really though, let me explain the goal I've had in mind. The folder "usr" stands for User System Resources and contains things such as libflashplayer.so. This file we've been dealing with is the Adobe flash library file and placing it in the "usr" folder allows all users and program access to it. Which is why it is installed there when the actual installer is used. I was avoiding putting it there however, because this manual installation does not tell a package manager where the file is located; making it difficult to keep track of later on if you choose to make changes.
So the goal I've had in mind is to place this library in the ~./mozilla/plugins folder. This folder is depreciated however, which is why we had to create it using the command "mkdir ~./mozilla/plugins", but it should still work. Now then, the "~" is a short hand way of putting in the current user's home directory. It is great for helping others because I don't know what your user name is on your computer. But from the output of your terminal I can infer that it is kremtok. So "~/" is the same as entering "/home/kremtok"
"/usr/lib/mozilla/plugins" is not the same as "/home/kremtok/mozilla/plugins" although I can see where the confusion would be, the locations seem to mean similar things. But as you've seen, anything not in your home folder requires root (or sudo-root) access.
It looks like our libflashplayer.so file ended up in /usr/lib/mozilla/plugins which I have no clue what goes in there
But this command should put a copy in the correct directory:
cp /usr/lib/mozilla/plugins/libflashplayer.so ~/.mozilla/plugins
The naming scheme for these commands are pretty straight forward:
cp = copy paste
mv = move
mkdir = make directory
Edit: oops! It looks like you've already tried that last command. Well, I've been avoiding it, but give this a try:
Edited by Fir3Chi3f - 3/3/12 at 12:58pm
sudo mkdir /usr/lib/flashplugin-installer
sudo cp /usr/lib/mozilla/plugins/libflashplayer.so /usr/lib/flashplugin-installer