Pick the funniest book you can find. Read it aloud. See who cracks first.

This is the nuclear option for kids who have decided they don't like reading. It works because you're not asking them to read — you're asking them to participate in a game that happens to involve a book. The book is the prop, not the assignment. And once they're laughing, the emotional association with books shifts from "boring obligation" to "the thing that made me laugh so hard milk came out of my nose."