Here are some basic instructions.
To install Firefox or Thunderbird on Linux:
Download the tar.gz package from www.mozilla.org
Look in /usr/lib to see if an earlier package exists - if it doesn't have
version number suffix you may need to save it.
Unbundle the package to /usr/lib:
tar xzvf /root/thunderbird.126.96.36.199.tar.gz
This should create a directory with the install usually without the version.
So you'll know later you should renamed the directory with the version:
mv /usr/lib/thunderbird /usr/lib/thunderbird.188.8.131.52
Make a link (check for existing executable first and save it if desired):
mv /usr/bin/thunderbird /usr/bin/thunderbird.old
ln -s /usr/lib/thunderbird.184.108.40.206/thunderbird /usr/bin/thunderbird
At that point you should just be able to start the application by typing the
command at the prompt:
Posted because this annoys me about the Mozilla site. It takes you cleanly to a place to download the package for Linux but then doesn't bother to tell you what to do with the .tar.gz you've downloaded. I had to figure it out for Firefox upgrade a few months ago then promptly forgot about it today when my boss wanted to install Thunderbird. The README.txt is a joke - it just points you at their site. The site in the "installing" section just says something like "this can be installed on Linux" which makes one wonder why they bothered with the README.txt or the link for "installing" on their site.