After a bit of brainstorming we decided that the best course of action would be to put her in a bucket until she calmed down a bit, and then using tweezers pull out the dead fish. So after a couple minutes of pulling on this corpse we managed to dislodge it, only to find the the from fins had turned into barbs. Our piranha is ok(I think) and she’s swimming around. I’ll put up a few updates, and maybe the link to the video if anyone is interested in watching how we got it out.