Glad to see another Alabamian on here (and even the same city as me, at that!).
I've never used a smokestick, but one thing I've found to be effective with my KR808 cartomizers is to take remove the cap of the carto, tilt the carto a bit, and drip the juice down the side of it. After every 3-5 drops, I hold the carto at the top (the end you put your mouth on) and shake it like one would shake an old thermometer. This forces the juice in to the filler.
I'm not sure what the "o-ring" you're referring to is, but if your cartos (remember, I'm not familiar with the smokestick) are anything like mine, the only thing you need to remove is the cap (and possibly a clear rubber ring directly underneath it), which should be replaced exactly as it was once you are finished with the refill.
I hope this helped a bit- and hopefully someone more familiar with your particular model of PV can lend us some more insight...but just keep at it! The biggest thing I had to learn was to treat the "how-to" videos as a general guideline and figure out what worked best for me, personally. There was some trial-and-error involved, but I figured it all out in the end!
There should be no need for gloves or anything- you're probably overthinking this- I know I sure did when I first started to refill cartos!