How to install Hadoop 2x version?

 -Conf files for 1.x
  1- core-site.xml
  2- hdfs-site.xml
  3- mapred-site.xml
  4- hadoop-env.sh
  5- masters   - It holds the information about Secondary Name Node (SNN)
  6- slaves

 -Conf files for 2.x
  1- core-site.xml
  2- hdfs-site.xml
  3- mapred-site.xml
  4- hadoop-env.sh
  5- mapred-env.sh
  6- yarn-env.sh
  7- yarn-site.xml