To be clear, this window is in my house, which I own. However I don't have a key that opens it.
Below is another window in my house (exactly the same as this one) which I do have a key for. I've shown it locked and unlocked & open.
I don't mind breaking the lock, but I still want to be able to turn the handle so that it's closed. How do I do that?
Edit: O-kaaaay... Here's what the window looks like now below.
In process of trying to turn barrel I ripped it out. Removing screws didn't help at all so put them back - impossible to remove handle without it being open first. Trying to force the handle with a claw hammer makes the window bend so much I'm afraid of breaking it. The handle hardly moves at all. I can't see a catch or any other magic thing to click in there. Please help with this massive mess I am now in.