Need guidance on installing CKEditor in Joomla

I am not sure how to integrate CKEditor into Joomla! 1.5.20.

I understand there's no installer package, and that you just copy the source folder into ~/web_root/ and call it whatever you want (default is "ckeditor") but then I get lost.

How do I get CKEditor to be the default editor to replace TinyMCE or JCEditor?

Some guidance would be highly appreciated as this editor is the best I have found so far. Only problem is activating it!