It sounds as if the hammers are down on both locks if the firing pins will not move back into the breech face. Your friend does not need to ship the gun across the country at this point, or remove the firing pin bushings either.
In all likelihood, he just needs to manually cock the locks. I made an L.C. Smith cocking tool identical to the one pictured in Brophy's book. But as I recall, they can easily be cocked using a 6" Crescent wrench, lacking the spanner.
Then I would take the time to look into why the right lock did not remain cocked when the gun was opened to remove the fired shell. It could be that your friend simply did not open the barrels fully enough for the trigger sear to fully engage the hammer, i.e., the hammer was not rotated back far enough. Since the left barrel had not been fired, that side remained cocked until he pulled the trigger. Or maybe he accidentally was holding back the right trigger, causing the same issue. On the other hand, it's possible the sear engagement is worn or packed with crud, and the hammer did not stay cocked for that reason. He would have to remove the lock to inspect the sears. If the sear engagement is worn or damaged, the gun could be prone to an accidental discharge. At that point, it would be advisable to employ the services of a good gunsmith.
This all presumes your friend has the correct screwdriver, and the ability to remove the lock without doing more damage.
