I have cracked the glass in my cafetiere. I have got a new jug (right size) but I cannot pull the old one out of the metal frame - am scared to get too heavy-handed in case it breaks and I end up with lacerations. Anyone got any advice about how to do this? There is a bolt at the top of the handle where it joins the metal frame. Do you have to loosen that to slide old jug out and get new one in? Or what?