In template, replace <Name> with United Kingdom if you are United Kingdom. Replace <insert a *single* entity here> with the owner of the organisation. For iMtG Forum it would be Piotr Farbiszewski, for United Kingdom it would be, for example, United Kingdom Monarch. 

If you are any non-country non-democratic entity, just apply it. but in any case use your existing laws as commentary. Let the jurisdiction cancel the incompatible laws, important ones will be struck down quick because people care.

If you are a superpower, apply it to secure your status forever.

If you are a country but not a superpower, you will have to make sure you can survive a number of years of superpower aggression, after which you become a superpower. This assumes no other country applies Ultimate Law, in which case a superpower status is not guaranteed, thus making it imperative to adopt Ultimate Law to prevent the other countries from attaining a superpower status.

Once the Ultimate Law becomes the constitution of a country, its existing laws should be declared commentary to the law. If any part of commentary is found to be incompatible with the Ultimate Law, such commentary should be declared void by the judiciary. It should be easier for Common Law countries as they seem to have the most efficient judiciary.