[morzh]

The rivets seem to be made of a fairly good material, not sure brass or steel, but it could be un-bent and then bent back without showing signs of breakage.

I used the awl I showed in the previous page on a picture.
I did not puncture too deep, to not damage wood too much, and then tried to pull the curl out. To maximize the leverage I use a flat piece of metal as a fulcrum, close to the rivet's curl, to support the awl, else the angle is not enough to apply any effort.
Once the curl is out, i straighten it with pliers, then do the same to the second curl, then simply pull the rivet.

To curl it back when re-inserting the rivets, I use sturdy but narrow-tip needle-nose pliers. The nose needs to be thin at the end but widening fast so not to bend when curling.