Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
These fittings don't have any obvious affordance for removing or opening them.
Try twisting the ring around glass part, or twisting the entire thing.
I suspect it's just the glass bit.
Grab it and twist the hell out of it to the left OR a big hammer.
Required, but never shown