They need to forcefully speak out individually and as a group against terrorism.
They need to do this every day.
They need to turn in suspected terrorists to the police.
That should be good for starters.
" They need to forcefully speak out individually and as a group against terrorism."
I agree. As should everyone regardless of their religion, of course. I've seen and experienced examples of this.
"They need to turn in suspected terrorists to the police."
Of course, again, as should any sane human being. Most, of course, will not have the need.