How do you apply postmodern theories to literature?

postmodern theory is characterized by new philosophical beliefs about reality, truth and language. postmodern literture responds to these philosohies and postmodern literary elements namely questioanable narrator, magic realism, metafiction, temporal distortion, metanarrative and irony etc. now to apply postmodern theory on a piece of literature it is essential to find postmodern perspectives in literature. i applied this theory on a Pakistani novel, Burnt Shadows by Kamila Shamsie and found questionable narrator, subjective truth, characters as social constructive self and some postmodern literary elements.