As LibreOffice is at the third beta stage it shouldn't be used in production environments but if you wish, it can be installed nonetheless.
** You can have LibreOffice sit along side OpenOffice, but if you want to remove OpenOffice entirely then enter the following command into Terminal **
sudo apt-get remove openoffice*.*
1 - Download LibreOffice from: LibreOffice Downloads
2 - Extract the file to ~/Desktop
3 - Rename the file to libreoffice
4 - Open Terminal and enter this command:sudo dpkg -i ~/Desktop/libreoffice/DEBS/*.deb
5 - Then enter the following command into Terminal:sudo dpkg -i ~/Desktop/libreoffice/DEBS/desktop-integration/libreoffice3.5-debian-menus_3.5.4-2_all.deb
You have now successfully installed LibreOffice.