How do I remove the bottle cap? I can't figure it out lol

You don't remove the entire top of the vial, just the little circle in the middle.  It has a ridge that you can either slide a fingernail under and pry up or you can use something like a pocketknife.

Unless you meant the twist top on the prescription bottle.  If so, press down a little and turn it hard to the left.

My last 2 came with a full metal top that came off leaving the metal collar and rubber top.

If you mean the glass vials:

About 2:30 he tells how to crack the vial properly.

Mine came with a green cap. That popped off. Under the green cap was the silver thing that's not meant to be taken off, just poke the needle through the white part.