How to: Update to Thunderbird 3.1 on BT4 R2

This is for the people who use BT4 R2 as their main OS (and also everybody else who's interested of course) and want to update to Thunderbird 3.1.

I found that the version BT comes with is rather old, but usable.

The n00b that I am, I couldn't figure out how to properly install the latest Thunderbird when downloaded from the mozilla website. The download contained no install files and I couldn't find a guide either (from the mozilla website I mean) and I didn't want to manually move the files to a directory to get it working.

I found a .deb file of Thunderbird 3.1 which I was able to install and now I can use perfectly.

Download Thunderbird 3.1 .deb file

I usually use gdebi to install .deb files. (I did not have any version of Thunderbird installed when I did this).
Be sure to backup you previous Thunderbird files.

When installed you can run "thunderbird" from the konsole or from the menu.

PS: I couldn't find the latest version (3.1.9) in a .deb file but if someone has a link, post a comment.