Plugins?

Hi,
Hi
I got the wonderful “random post” plugin, but i have a problem.
I’m running wordpress 1.0.2, and I can’t find, in my admin page, the plugin administration one. So I can’t activate it.
Is that in a newer version than mine?
In case I need to upgrade, please help me! I did some modify in the index.php age, and in the wp-layout.css, I don’t want to lose all my stuff 🙂
Thank you in advance
Simone Borselli (Italy)