It might also make sense to run through the rest of the requirements in the preceding and following sections to the discussion.
As the section pointing to that path indicates, you would be doing those changes AFTER manually installing the agents and daemons package.
I would reccomend doing a root based install until you are familiar with the documented installation process. You would follow the "Path B" installation discussion to do this (configure repo based on your linux distribution type, install agents and daemons packages).
what OS are you installing over?
Feel free to use path A as well! It is by far the simplest approach to setup and configuration so that you can get into using the platform quickly.
The path B approach lets you manage the installation manually using packages, and would be what you want to do for a production deployment that you intend to run long term.
If you have previously attempted install, search for "uninstall" in the installation guide in the docs (top left of docs pages to search) and it will give you the cleanup steps to apply to your previous installation attempts.
RHEL 6.4 is fine to use 6.5 is supported as well, the actual OS, database, and JDK requirements are listed in the sections around the link I gave for the single user mode discussion as well.
Keep us posted on your progress, feel free to start a new topic to address the specific issue you see.