So finally rehabbing my olds cutlass(69) convertible. She has been sitting (garaged) for about 10 years. So I tore out the carpet and have two area of floor that need to be patched. The problem is the support/ floor brace is badly rusted as well. So I was wondering is it possible to replace this brace without removing the body. It looks rather tight where the brace goes over the frame and attaches to the rocker panel.

 

It may be possible, but it will be difficult. Not much room between the frame and the rocker panel. You may have difficulty cutting out the old brace at the rocker panel as well as welding. If you are to leave the body on the frame, consider cutting a wider area of floor to patch so you have room to work. See attached picture of my 69 conv with the floor removed. My braces were fine, but easier to replace the entire floor than patch it here and there.

 

It may be possible, but it will be difficult. Not much room between the frame and the rocker panel. You may have difficulty cutting out the old brace at the rocker panel as well as welding. If you are to leave the body on the frame, consider cutting a wider area of floor to patch so you have room to work. See attached picture of my 69 conv with the floor removed. My braces were fine, but easier to replace the entire floor than patch it here and there.