First get rid of fragments. If the fasteners remain, they should be carefully removed with a chisel. Remove the putty and take entire pieces from the grooves. If necessary, they can be cut into glass cutter. The old putty is removed by a spatula or chisel. To accelerate the process, you can slightly heat it with a hairdryer. With ticks, remove the holding cloves. Next, you need to clean the groove for glass with sandpaper. Then we apply a thin layer of silicone to the bottom of the grooves — it will serve as a seal. We insert the glass and strengthen it with stacks or cloves. It remains only to apply a putty and the window is ready.