How can I fix the upholstery on the sides of my car seats?

Does anyone know the answer to this one please?? The seams on the upholstery on the sides of my car seats are coming away from behind the hard plastic airbag covers. Someone has tried to glue previously but this doesn't work as they need to be reinforced and stitched in place to hold it. Can the plastic airbage covers be removed to access the upholstery or will this deploy the airbags??