I need to remove the "www" part of a site's URL. Is it posible to simply go to settings and change both the Wordpress install URL? Or there's more steps involved? I'm a bit wary of changing the Wordpress install URL, I don't want ti to kick me out of my own install and not being able to access the site anymore but can i do it safely?
If you want to change your WordPress Address (URL) one option is to make use of this tool: http://interconnectit.com/products/search-and-replace-for-wordpress-databases/
Just download it, upload it to your server, extract its files and access it via your browser.
Suppose your WordPress Address (URL) and your Site Address (URL) are "http://www.example.com" (without quotes obviously). So if you want to remove "www" I recommend you replace "www.example.com" with "example.com".
Just make sure you first backup your database before doing anything and also before clicking on "live run" you should perform a "dry run".