The ribs are severed from the spine and the lungs pulled through the opening to create a pair of wings.

FAR easier said than done without chopping and mashing the lungs into a gooey mess in the process...Like "I'll tear off your head and shit down your neck," this seems a fanciful and imaginative threat that's super difficult, messy, and not very anatomically realistic to carry out.

With today's modern power tools, sure...a thousand years ago I doubt it

The ribs are severed from the spine and the lungs pulled through the opening to create a pair of wings.

FAR easier said than done without mashing the lungs to a gooey mess in the process

With today's modern power tools, sure...a thousand years ago, nah