Step by (tiny) step.
Write what you want small.
Select it. Click size, change to a different size.
Want smaller? Simple, click the source button. It will look weird, don't worry. HTML is your friend.
Find the text you small-ified (a ctrl-f (tiny) would find mine, for instance). Before it, there'll be a font tag "font-size:10px" for instance. Change the 10px to 1px. Voila, you too can tinify things. Don't be a dick with it, don't make it 300px, or 1px for no good (or funny) reason, and have a look through some HTML tutes. It's basic stuff and you can do some interesting stuff with very little effort.
Or, y'know, flail around in a forum asking how to do something simple. THat works too, but is far less self-reliant and impressive.