Years ago I used to break lots of the studs holding the red reflectors. I then came on a way to not break them and have successfully removed MANY since then.
Using a propane torch or a heat gun, either one will work, I heat the plastic stud for about 2 seconds with the torch, maybe a little longer with a heat gun. Then I remove the nut. It comes right off easily after applying the heat. As the stamped steel nut comes off the warm plastic stud it makes better grooves in the stud so when putting it back on the nut is not so tight and goes back on easy without the chance of breaking the stud.
Thanks to Jim Finn, member of the AACA Reatta forum, for this information.