I just changed dashes on my 126 SE I cut a 2x4 so that it fit between the floor and one of the steering wheel spokes padded the top of the 2x4 and used a breaker bar and a good 10 mm hex scoket
with no give it broke loose where as it would not with some one trying to hold it.take the carpet out so you don't crush the plastic rear heating duct..............

William Rogers.........