If there is a hole through the ceramic you can approach it from behind. Start by carefully scraping away surface glue with a razor blade.
The pic shows a CLEAN insert on top, aftermarket on bottom.
After the glue is scraped away you can try gently prodding the metal with the tip of a springbar tool or similar. Lay the insert face down on dense rubber mat. This will give it a firm base with a little sponginess. Be extremely careful as ceramic cracks easily especially at a weak area like where there is a hole.
The pearl probably won't give way yet but it's worth a try. Next, use a tiny artist brush to drip a drop of acetone (Goof off) into the hole to dissolve more of the glue surrounding the pearl cup. You can work the brush around against the metal to help soften the glue. Then try the gentle prodding again. Do not flood the area with acetone and don't let it flow onto the insert topside. Acetone will eat away the marker fill.
Rinse and repeat til the pearl cup gives way. You may be left with some glue stringers preventing the cup from pulling away, cutting them with manicuring scissors is easiest. Sometimes the glue is too rubbery and stretchy to use a razor blade. Avoid getting the acetone onto the triangle marker fill as much as possible. Use tweezers to pull the pearl away while keeping the insert anchored. Tape it down if you have to cut stringers while pulling the pearl away.
Once the pearl is out, clean off all excess glue. You can use a razor or a micro drill bit to gently ream out the hole interior. Do I need to keep mentioning how careful you need to be at the ceramic's weakest point?
If there is no hole through the insert, or if it just won't budge after the above actions were tried, you'll have to approach it from the front. This will almost certainly ruin the triangle marker fill so a paint mod there will be necessary. Do the paint mod before gluing the new pearl in place. Make every effort not to get acetone onto any of the other markers. A well done triangle paint mod can be off a little in color and not be noticeable because of the pearl. But having to redo more markers can escalate into redoing the whole insert. See links below for a paint mod.
Put drops of acetone into the triangle and use the brush to agitate the mix. You can tilt the insert triangle down toward you and let the mix run off the edge onto a paper towel while you brush it away. Keep adding fresh actone. Eventually the glue will loosen up enough that you can grab the pearl with strong tweezers and exert a rocking pressure on it to separate it. You can also use a toothpick to try to pry it up on one side.
If you still can't get it off, or you are willing to just do a whole insert paint mod from the start you can just soak the whole insert in a small bowl for 30 minutes or so and lift or pry the pearl off. Cover the bowl in this scenario with plastic wrap or put it in a ziplock bag as acetone evaporates quickly. If your insert is a cheap aftermarket one with white marker fill, with most of those the fill won't budge even with acetone so that makes things much simpler.
Insert paint mod - spray paint
Insert paint mod - latest recommendation