The first thing I'm noticing is that your cats have no reason to eat the wet food. They can go get some tasty snacks (kibble) whenever they want! They may feel that there's no urgency in eating the wet food, or they may not care for the flavor or texture; particularly when compared to kibble, wet food can taste a bit "healthy," as it isn't sprayed with all the flavor enhancers used to make kibble palatable. You can think of it as a plain baked potato (wet food) compared to a potato chip (kibble); the chip may taste better, but the baked potato is healthier.
So start by reducing their free access to kibble. Don't refill it as soon as they can see the bottom of the bowl; measure it out and let it run empty, preferably some time before you offer the wet food. If they can't just run to their kibble bowl, they're much more likely to give the new stuff a try. Give them a little bit of canned, preferably in a similar protein profile (flavor) to the dry so it's a more palatable transition. Offer the same food for at least a week--don't immediately panic that they aren't eating it and switch to another. Give them time to get used to the idea. If they still aren't eating it, try a different texture; wet food comes in pate, chunk, and shredded varieties, and many cats will prefer one over another.
When they've found a wet food they like, start increasing the amount you're feeding while slowly decreasing the kibble. You're doing a phased switch at this time, encouraging them to eat more of the wet and less of the dry by letting the dry run out sooner; only fill the bowl after feeding the wet food, and don't fill the kibble bowl immediately after they leave the wet (or they'll learn faster than you might think possible that walking away from their baked potato will get them chips!)--you need to give them sufficient time to eat the wet food before offering the alternative. You'll also need to be measuring how much you're putting out, so you can decrease it.
Note that I'm not suggesting you starve them out! A cat shouldn't go more than a day without food; give them a reasonable amount of time to eat the wet, but make sure they're getting something, especially in the earlier stages of transitioning them. Make sure you're prepared to resist their begging, too; as soon as they discover that the unlimited buffet is running low on food, they'll be doing their best to guilt you into filling their bowl. You'll need to be more stubborn about moving them to wet food than they are about staying with the dry. They will fight you on this, so dig in your heels and don't let them win.
It'll take time, especially if they've been eating dry (and getting their way by resisting the wet) for a while, but it can be done! You're already on the right track by having scheduled feedings with the wet food; take note of how much food you put in their kibble bowl and how much it should be to have it start running out right around that time (measuring cups are a big help). Be patient, be willing to let some food go to waste, be willing to spend the time that it takes to find what they like, and you'll come out victorious at the end.
The site for cat hospital Cats Exclusive Veterinary Center has an extensive write-up to help transition, if you'd like even more details on how to proceed. Note that the write-up is a bit older, as one of the brands suggested for grain-free/low carb (EVO) was discontinued several years ago, but the core information is still very useful.
