needle yes.You remove the top mouthpice tab with some tweezies..if ya got some good ones

..then remove teh second cap under it...Youll see teh fill port in teh dead center under those two. Puncture that, and fill from there.
If you cant do that, then just fill from teh bottom hole, but might take a while. They hold 2 ml easy.
But best fill is
through top port. You can shove a 6ml bottle up the cartos .... to catch the drips when filling. Once it stops dripping, its full and ready to chief. Refill with half ml to a ml a pop.