The files you have extracted are for chromium based browser. The old instructions were for NPAPI Flash Player.
If you are using firefox then you are taking the wrong tar.gz. Please use the NPAPI Flash Player tar.gz file.
If you are using chromium based browser you could run the browser through command promt using command "sudo <path to browser executable> --ppapi-flash-path="<path to libpepflashplayer.so>" --ppapi-flash-version=<Flash Player version e.g. 126.96.36.199>"
what linux distro are you using?
I use linux from scratch 7.7 (64bit).