Mark the spots using a pencil. On the highest and bottom of the window frame, measure in 60 centimetres (24 in) from the proper and remaining sides, and mark these spots at the same time. Use your electric drill to produce pilot holes above the pencil markings.[ten] X Exploration source https://josuegdyqj.theisblog.com/31031168/not-known-factual-statements-about-upvc-windows