How to Install Oracle Java JDK 6 in Ubuntu 15.04 14.10 14.04 13.04 12.04

1)
Add Repo

#sudo add-apt-repository ppa:webupd8team/java

2)
Update Repo

#sudo apt-get update

3)
Install Oracle Java 6

#sudo apt-get install oracle-java6-installer

4)
To automatically set up the Java 6 environment variables

#sudo apt-get install oracle-java6-set-default

5)
Check Version

#java -version

6)
Remove Oracle Java 6

a)
Check which JDK packages are installed
#sudo dpkg --list | grep -i jdk

b)
Remove Oracle Java 6
#sudo apt-get purge oracle-java6-installer
OR
#sudo apt-get remove oracle-java6-installer

c)
Check that all JDK packages have been removed
#sudo dpkg --list | grep -i jdk