There is a set of hooks etc for installation but indeed it involves drilling. I found a non-invasive way with plastic hooks which are commonly used for mounting anti-bird installation on roofs or so. They are ca 3x4cm, transparent, flat on the bottom and they have a tiny hook on the top surface. You glue them bottom side to flat surface (floor, wall, ceiling, any other stable/solid surface). Then you hook the net to them. You will need one every 10-15 cm to keep the net solidly mounted and stretched (so that your cat doesn't get inbetween the hooks under the net)