There are two methods you can use a pvc cladding to replace your current fascia. The first method is to start by removing the old fascia boards and the first row of tiles which are above the guttering and beneath the first row of tiles. Next, fit a bendy plastic strip. Finally, fit new fascia boards. In the second method you just cover the original wood with PVC cladding. If you use this method, make sure that you provide ventilation to the soffit boards to prevent condensation in the loft space.