They write up the study, submit to a peer review journal. Popper, Kuhn, Lakatos, etc. (look at the reading lists from an philosophy of science grad-level course), describe how it may become established if it is a big finding (I'll let other commentators say what it would take to become a "law").

In the old days a person might read a paper to a society (e.g., the Royal Society in London) and it would get comments there. That still happens on a few papers (though some of the comments are often submitted electronically later). See Behavioural and Brain Sciences for something like this. Giving talks at departments that focus on the topic is also a good way to see if the finding is important and it helps to get people to know your research.

First of all the result should be published in a peer reviewed journal. It should be uploaded in a database like researchgate which has global visibility. This secures the copyright against possible piracy.

Then it can be presented in seminars or conferences. Contributions shall be received and finally the result will be put as a law by a professional or academic body.

Note that such process may take a long time. For example, getting some road safety innovation into real life may last 2 decades (see the reference). Good luck!

Conference Paper Innovation and Safe System Road Infrastructure

Thank you for your swift response. Time to complete is not that critical so long as I am in the right place with the right people.