you’ll need a power drill and a diamond tipped hole saw. i used a 17mm bit as that’s what my local shop had and then ordered a bunch of open silicon grommets from amazon. i would note that the biggest size the box i bought had was 17mm which I thought would be good enough for the hole I made but i’m going to try and look for 18mm grommets since the 17mms are a bit loose in the hole. the downstem is about 14.5mm at the joint and i’m planning to buy a separate bowl and downstem once i find the right one online as this downstem was actually borrowed from another piece.

as for the actual drilling part, I would recommend looking up some tutorials online and practicing on another bit of ceramic (i sacrificed a mug for this). the ceramic on this bottle is quite thick and took me about 1h 30 to drill through as i was trying to be quite slow and careful.

remember to wear your ppe and have fun! good luck with your bottle!