Delete the current LICENSE file in your repository and replace it with the new one.

You don't have to put your name, year etc anywhere, the license is valid for the entire repo. You are not filing for an IP, it's just a usage license.

Note that all the legal jargon is not necessary, you can write one yourself as long as you make it clear what you allow and what you don't allow.

I.e. "don't be a dick" requires elaboration, "do not use my code if you intend to make money off of it or parts of it" is clear and legally binding.