I ran into this with my towncar. A400lb pig at the factory must have put his weight into it when the body was off. I almost broke my hand. On one i cut it off and used a 6 point socket. Vice grips on one. The bracket bends so i pried a bar against it opposte direction, but who cares about ford paint, so try like fy1 said.
I"d cut it to get it in a vice and make up a new line. So easy, just non metric flare, no antilock. I went thru hell finding 2 different size adapters converting non metric into metric din bubble. One american brand leaked. Took a Chinese one to work. Autozone had crap for adapters, advanced auto had them. Don"t waste another week, cut it out if you have too.
Vice grips still should get it. Have someone keep the valve from twisting in the same direction as the vicegrip.