First download the file for your OS, then extract the DEBS
tar xvzf LibreOffice_6.####_Linux_x86-64_deb.tar.gz
Then install upgrade with this command
sudo dpkg -i LibreOffice_6.###_Linux_x86-64_deb/DEBS/*.deb
First download the file for your OS, then extract the DEBS
tar xvzf LibreOffice_6.####_Linux_x86-64_deb.tar.gz
Then install upgrade with this command
sudo dpkg -i LibreOffice_6.###_Linux_x86-64_deb/DEBS/*.deb