On those stubborn carbon packed heat shields, one trick that has always worked for me is to take a 1/4" dia flat face punch and a hammer, tap all around the outer diameter of the heat shield. This breaks up the carbon and the heat shield comes out easily with a magnet or a hook. No solvents needed.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked