Hi, I'm hoping someone can help. I have a window with non lockable handles (see below picture). I had been hoping to replace these with new handles which were of the same design but lockable. However, as you can see the handle is rivetted onto the window rather than screwed on. Just wondering whether a)anyone can advise on how to remove the handle or b) any way to make the existing handles lockable and c) what purpose does the threaded part have? Any help would be much appreciated!
