It seems Your plan B might Be to leave them in, return the PCV, & get a reflash on Your computer module.
I encountered trouble on My last butterfly, so I drilled the head off. I used heavy grease on the drill bit to catch the chips, & did a thorough shop vac on the air valve with a piece of clear tubing and some duct tape. It is possible to drill them all, but if you have never done anything like that before, I wouldn't recommend it.