Can I modify the Settings.php file?

[Aspirin]

I'm quite new to this forum, and I have some issues. Whenever I go into the "Edit Server Settings" in my admin page, I get a message at the top of the page that says "These settings cannot be changed because Settings.php is read only." and all of the boxes are inaccessible. Now, the last thing I did was I tried to manually edit my settings in the settings.php file, and I wound up screwing my forum up beyond repair. I'm wondering....how can I make Settings.php editable and not read-only?

[[Unknown]]

How do I use chmod?

-[Unknown]

[Aspirin]

Thanks!!! I'd been wondering if changing the permissions would allow me to modify the file. That helped quite a bit!