I had this happen on 3 of the four belt end parts where these little bolts cammed out and I can’t get them off to trim down the belts and re-attach.
I have not tried this here, because I’m just going to print them on my 3d printer and cut off the old ones, but I have had some luck in other situations like this taking a thin rubber band and using it between the driver and the bolt to gain grip enough to get the bolt started.