Can I take down the window as a security net?

Yes

Use the expansion tube disassembly method.

If the bolt and nut rotate together, fix the gap between the wall and the expansion pipe with a pin, so that the wall and the expansion pipe are closely connected. After unscrewing the nut, remove it according to the previous method. You can buy a sleeve and remove the expansion screw. You can take off the nut and pull out the bolt with pliers. After pulling out the coat, the screws inside are not a problem at all. Remove the nut, slightly knock in the screw, then take out the expansion cap of the expansion screw with the needle-nosed pliers, and then take out the screw. It takes some effort. There's an easier way. Knock the screw in a little first, take a screwdriver or a vise, pry open the connector of security window directly, and put it back without even screws.