What tool do I need to cut through the metal of a computer frame?

I need to cut some pieces out of my computer frame to make more room. What tool do I need to cut it and how much is it and what is the cheapest alternative?

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).