create an account with the W3C's community group system. Then, join the WHATWG community group. Then make the patent commitment by following the instructions on this page (pick the first radio button, then click "Record my choice"). That's all there is to it! Google, Mozilla, and Opera have already signed the patent commitment agreement. Anyone can sign up, but it's even more useful if you are an employee of a big patent-holding company and can convince your company to sign up!