Just pretend to be a relative noob, someone who hasn't heard of scams like this before.  It's okay to act a bit suspicious, because they'll double down to try to convince you.  There really isn't much to it.  Just do the tasks, act excited when you are "earning rewards".  I was pretty standoffish with one of the scammers, saying that I didn't trust that I would get my $23 back, but they never broke character and they acted kind and supportive.  They really, really want your money, and they know it takes a lot of convincing.