If so, they are apostate and must be put to death. Plenty of other ways they can die even if they remain Muslim, such as stoning, honor killing, etc. Too bad for them.
When my niece was in college, some of her friends claimed to have converted to Islam. I asked one of them once when she was going to start killing Jews, as required by her new religion. She didn't answer.
“when she was going to start killing Jews, as required by her new religion.”
I very much doubt God told Mohammed to rob caravans, rape captive women or kill Jews.