Vombil thank you for previous advice as I drilled out the old Tonneau clips with my office hands, no problem / no damage. Started with a very small drill pilot hole and then larger size to drill them out. Looked at a previous post about fitting the Tonneau clips, and Jennie and Rodney from Parkes had used a heated punch to expand the clip holes before inserting plastic rivet. Used our family sandwich maker to heat up the punch (perfect temperature) and was super easy to sort them out.