Remove Oracle JDK Ubuntu

1. Remove the link:
   

   sudo update-alternatives --remove "java" "/usr/lib/jvm/jdk[version]/bin/java"
   sudo update-alternatives --remove "javac" "/usr/lib/jvm/jdk[version]/bin/javac"
   sudo update-alternatives --remove "javaws" "/usr/lib/jvm/jdk[version]/bin/javaws"

2. Then, remove the package in the /usr/lib/jvm
   

   sudo rm -r /usr/lib/jvm/jdk[version]