How to install LibreOffice 5.0 in Ubuntu?
Simply use the official PPA :
sudo add-apt-repository ppa:libreoffice/ppa
sudo apt-get update
Option 1 : You don't have libreoffice
yet :
Open a terminal (Ctrl+Alt+T) and run:
sudo apt-get install libreoffice
Or install using Ubuntu Software center :
Option 2 : You already have an old version of LibreOffice (4.x) :
Open a terminal (Ctrl+Alt+T) and run:
sudo apt-get upgrade
If you are looking for RC5, you can try
Libreoffice Packaging Team
sudo add-apt-repository ppa:libreoffice/ppa
Or
Libreoffice Pre-Release
sudo add-apt-repository ppa:libreoffice/libreoffice-prereleases
Keep in mind they are early releases and unstables versions.