Welcome to LQ.
You have found one of the worst methods ...
* No reason to remove openjdk : You can have as many java versions
as you want, installed at the same time.
( There is a "change version command" in Ubuntu :
$ sudo update-alternatives --config java ).
* Etc. etc. rubbish in that instruction.
( Do not believe everything written on the Internet ).
The easy way :
Google .. java7 ubuntu 14.04 ..
The first hit http://www.enqlu.com/2014/03/how-to-...8-jdk-and.html
$ sudo add-apt-repository ppa:webupd8team/java
$ sudo apt-get update
$ sudo apt-get install oracle-java7-installer
.. and you can immediately type $ java -version
.. and get the reply "Java(TM) SE ...
.... 1.7.0_55-b13 ..."