There might not even be a need to change a science law. The introduction of a unique fully realised device working within current scientific laws can be worked the same way. Likewise, the same applies to unique individual characters or species. As the author, there is a need to examine how far this will change society in general or characters in particular. Your task is to make the setting so real that readers are drawn into this reality.
Practical demonstrations are far more important than technical double-talk.
There is more going on behind the written page' is probably more fundamental of SF than any other genre. There is no need to give scientific explanations providing the demonstrations are internally consistent. No doubt some genuine scientist will correct or even justify what you've done, providing you've been applying a consistent logical rule structure. There will always be an opportunity to revise, correct or justify any problems found in another story. A lot of the SF Masters were smart enough to keep it confined to being recognised by a few characters.