It would have to be total extermination of 1.5 BILLION people and then a massive campaign to wipe out any vestige or history of Islam.
I think a lot of people would have a problem with that even if it were feasible, which is doubtful.
There are Christians who have been practicing their religion in hiding in places like China for over 50 years so even they could not wipe out Christian ideology. And they were pretty good at extermination.
Not really. All the Aztecs weren’t killed. All the NAZIs weren’t killed.
They just have to be crushed. Totally crushed.