Install Arduino IDE on Ubuntu

I have recently followed the installation instructions on this page http://playground.arduino.cc/Linux/Ubuntu . For Ubuntu 12.04 & newer. However it installs V 1.0 of the IDE and I would like to install version 1.5.7 There is a comment on the installation instructions stating "After the installing the stable version, development versions or nightly builds can be downloaded from the arduino.cc servers, unpacked anywhere, they run out of the box (as of August 8 2013, tested with Uno R3)" I don't understand how to do this. I have downloaded the version I want now how do I update or install it?

First of all, remove all Arduino from the repositories.
Be sure that “arduino” and “arduino-core” and “arduino-mk” and any other arduino are removed, before you continue.

You need most of Java installed to run Arduino (also the Java libRXTX). Sometimes the Java from the repositories doesn’t run very well with the Arduino IDE. The new BETA seems to use Java in a different way. I don’t know how yet.

You can “install” Arduino IDE in any folder. Just unpack it and run it.
Open a terminal in the unpacked folder and type: ./arduino
You can also create a shortcut to it.
It is possible to have more than one Arduino IDE on your computer, just run the one that you want.
Set your Arduino projects folder (with your sketches) in the settings of every Arduino IDE, and you can try the BETA or run the normal version and test the nightly builds.