So far, what's working slowly is safety glasses and 2 pairs of pliers. 1 set on each side of the primer or near it and bending the tough plastic. Sometimes a primer will fall out and sometimes I have to tear plastic away from the primer. Plastic rather tough for a razor knife to cut deep enough into it. Got 32 primers free so far. Lost 1 to it flying through the air into parts unknown and 1 fell into a garbage can that had lots of spent primers already in it.