“People have been counterfeiting bottle caps forever, but it's always been small scale. A bottle cap press is a whole other threat. We can't have anyone devaluing our currency by mass producing new bottle caps.”— Alice McLafferty
Go to the headquarters and locate the bottle cap press, which is found in the shipping area. Once in the shipping area, there are 4-5 Sunset Sarsaparilla robot employees that are hostile. The press is between the two stacks of crates in the middle of the shipping area behind a dead worker and near a box with 6 bottles of Sunset Sarsaparilla (the only ones found in this room).
If you haven't already, you can manually activate Mr. Janitor with a Science of 50. Use the terminal next to the robot to activate him. After Mr. Janitor cleans a few rooms, it will dispose of 500+ caps in the garbage can closest to the room you found it in. Do not talk to other robots while it is cleaning. This may cause it to stop cleaning and attack you. Mr. Janitor will not activate a second time. After activating Mr. Janitor, wait outside the room for a few minutes, then he will come back and put the caps in the garbage can outside the door with the 250 to 600 caps (depending on Luck, skill etc.)
Unfortunately, the cap press cannot be used by the player to make their own bottle caps.