Like someone else said, the Ressurectors will come with a syringe to fill with. Their are other ways to fill, but I find a syringe is the quickest and easiest way. The Ressurectors are big and hold 2ml of juice so it takes a lot to fill them. Thats why I recommend using a syringe with them. And like someone said, the first fill is VERY important. I find that the syringe is the best way to ensure its done right, but you can fill them anyway youd like. You can drip into the top of them or use the condom method too. I find that the condom method doesnt always work well though with big cartos like the Ressurectors and the drip method can take awhile because you have to wait for the juice to settle to the bottom, and if you dont wait long enough for the juice to settle you can potentially singe the wick and ruin the carto, so be careful if you drip into them.
I wrote this in another thread for someone who asked how to fill a Ressurector with a syringe so Im gona copy and paste it here.
Like I said its up to you but I find this to be the easiest and quickest way to fill the Ressurectors.
How to fill a cartomizer with a syringe:
"All you have to do is take the dropper part of the bottle off your juice and fill your syringe with 2ml for a new carto. Take the rubber tip off the carto and carefully insert the needle down the side pushing against the metal. DO NOT go thru the filler because it will move it and you could potentially break a connection and your carto. Slide the needle down the side and go all the way to the bottom. Then slowly start dispensing some juice. Dont dispense it all bc then it won't be evenly distributed. Put alittle in, then take it out and insert the needle in a different spot. I normally do it in 3 spots (in a triangle) I found it distributes the best, but you could just do it in 2, on opposite sides. Make sure the needle is at the bOttom bc then you will not have to wait at all for it to settle. Disperse slowly and you will begin to see the toP of the filler become slushy. It is full then, don't put more. If its a new carto is will def hold 2ml, if your refilling it won't take a lot so pay attention and once it gets alittle slushy stop. While your filling hold a napkin or something under the carto bc if you do it too fast a few drops will come out the battery end. If that happens its only bc you did it too fast and the poly fill didn't absorb quick enough.( that happens to me bc I am impatient and fill it in about 10 sec, so I just hold a paper towel or napkin underneath.) wipe up the drops and put the rubber cap back on the carto. Then put the carto between your hands and rub back and forth spinning the carto quickly. This will insure the liquid is evenly distributed in case you put too much on one side from the syringe.
Now you have a perfectly filled ressurector that is ready to be used right away!"
They dont come with instructions on how to fill with the syringe so I hope this helps. Id recommend at least trying it, and then if you dont like it, you can fill a different way. I know it seems alittle intimidating, but its very easy and youll get good at it quickly. The first fill is def important so I would at least do the first fill with a syringe. Then for refilling and topping off you can just add a drops in the top if you dont love the syringe. I fill and refill my Ressurectors with the syringe that comes with the Ressurectors and I find that syringe to be perfect for filling cartos. When they are filled right they normally last longer. Ive been using the same Ressurector for 4 and a half weeks with one juice I vape regularly.
Goodluck with it!