Share 'Questions about a Crestworth lamp'

Hi, I just got my first Crestworth. It's a Telstar Living Jewel. I've got few questions: - How do you remove the cap? (is it glued?) - About 1cm of liquid is missing, what can I put in it to get it level? - I don't see so much Living Jewel bottles, is it rarer that Glitterlite or else? Thanks