I hate those "simple DIY" instructables. Just had to build something I had to get. Found out one "simple DIY". It requires owning a power drill with a table mount. And a pipe threading machine. Yes, I surely have a drill mount for drilling thru some steel, I know how to use a CNC machine, and maybe have a little metal foundry in my flat. But hey, it's a DIY not 'go to nearest store and buy that friggin piece you need' so you should have prepared yourself for some difficulties.
It's not supposed to be easy!
I still wonder why the author not assumed everyone own a metal foundry, after all. It would be much easier for all of us.

And I ended using PCV, glue, and a spare bottle. Had to buy drill for glass, less than $3. Wasted few bottles to cut out what I wanted. Beer was quite good, thou.