Hi everyone, I thought I would contribute to the community and not be a leech by making a couple of tutorials here.
So anyways if you want to upgrade IPS 4.2.x to any other version, it'll be easy.
Nothing should go wrong, but it's still recommended to make a backup of the public_html/htdocs folder or wherever you installed IPS and the MySQL database.
Download the version of IPB that you want, and extract everything there to where you installed IPB except for the conf_global.php and the uploads folder.
Go back to your website and go to the /admin/ folder of your IPS installation and there should be a button there that says Upgrade Now, and you will want to click that.
Now just perform the upgrade and enjoy your upgraded installation of IPS!