It's as easy as getting a non-runflat tire of the same size.  BUT you don't want to do that.  You have runflat tires because you do not have a spare tire.  if your runflat  tire goes flat, you can drive at least 50 miles at 50mph on it.  If you have standard tires and you get a flat, you can drive 1/2mile at 50mph and then call a tow truck, because you've just shredded it.
   If you change wheels, any TPMS sensors mounted to the wheels MUST be installed on the new wheels.  Federal law and the TREAD act makes it a federal crime to disable or remove any part of the system, including the sensors.  You don't want anyone to go to jail just for that, do you?

yer you can do it just as long as you don't like in the usa. all you need to do is use the reset  button under your
handbrack.

i have had 20's on my mini so what a load !!! and to old bill dont give a

its also a felony to remove the airbags on any car without being certified but that didnt stop me  when the last time you saw someone get arrested on the news for taking stuff off their car?

You don't have to have a  runf-flat in your MINI if you don't want too.  Changing tires (in USA) is not a crime and you might change size if you like.  All season run-flats are OK with normal winter conditions (no heavy snow) and summer.