Need help - how to remove metal cover in stake hole pocket

Hi everyone - I bought my truck used and learn something new every time I work on it. I am installing retractable anchors in the stake pockets on my bed. The rear stake pockets were already exposed so it was easy for me to install the anchors. But the front stake pockets have this metal cover with a screw hole mounted inside of it. I am not sure if this is a factory configuration or a custom configuration. I would like to remove them and if any of you have faced something familiar I would love to hear how you did it as I can't seem to figure out how to pull these covers out. Attached some pics for reference. Give the factory paint color I assumed this was an oem option but I could be wrong and prior owner painted. Any help would be greatly appreciated.

 

Take a peak from down below and see how they are attached, maybe just need to thread a bolt in and tug.
Definitely not oem

 

Yeah very likely you can drill through the hole and then the anchor bolt will fall off. Take a peak from the bottom and you'll get a better idea of it.

 

Thanks so much for the suggestions. I threaded a bolt into the hole and pulled up. It moved a little bit but it is definitely in there good. I then stuck a long rod into the hole to see if there is a bottom but when I dropped the rod it fell out the bottom of the truck! So the threaded bolt hole is aligned to a drainage hole in the bottom of the bed. I am trying to find how they managed to affix this metal cover as there are no visible bolts holding it in place. Thinking I need to remove the bed cover moldings to see better but those holes are too small to run a bolt through perpendicular and attach right?

 

You could try threading a bolt into the threaded hole and using a pry bar with block of wood or metal as a fulcrum to pry the insert out. You may have to work around the insert from different positions to free it, but it's probably the easiest option without alerting or damaging the inserts.

Also, lube all around the edges good with a penetrating lube or 3 in 1 to make things easier.

edit for lube suggestion.

 

I was able to talk to the previous owner. He fabricated there plates for a custom bike rack. They are mounted from underneath with a bolt. He used a super long socket extension to get in there and tighten. Now I am looking for a super long extension to loosen and drop them out. Thanks everyone for the great advice and sleuthing. I thought these were factory covers until everyone shared they are not which prompted the call to previous owner. Thanks again!