I suspect that your puzzlement stems from a lack of understanding of Islam. - Islam is not followed due to belief, it is the law in islamic countries. One follows Islam from birth because if one does not, he loses hands, feet, sex organs, or his head, depending upon the extent of his heresy, and what the Mullah had for breakfast.
To 'convert' such people to anything merely requires sufficient threat of violence, since that is the basis of their culture. - The article was Satire; get a grip.
And your solution to this is to forcibly convert them to Christianity? What body parts do you plan to sever should they fail to comply?
I read the article when it was first written. It was not satire.