If you don't have that caliber, trade or sell them. If you just need/want the primers for something else, and they are not crimped in just use a regular sizing die to deprime, just go slowly and wear eye pro. You may detonate one or two, but most will just pop right out.
If stored right, they should be fine. My reloading bench is in the basement, I keep my dehumidifier running constantly. I keep primed brass either in ziploc bags or "dry" boxes. As long as the humidity level is not high and the climate is pretty constant yours should be fine.
Still have some that are over 20 years old, here in TN, so they were in a pretty humid environment. Haven't had a single one fail so far, they are pretty hard to kill, even on purpose, heck have even had some spent ones pop in the outdoor firepit when I placed some cardboard boxes I used to catch the spent ones in the fire, must have been trapped under the flap.
