Not sure if this helps? but once the nails are out, would it seem a good idea to drill in the nail-hole right thru the cabinet-side, therefore leaving you access in future to punch the nails out from the inside with a blunt tipped nail.
This would allow you to tap them out from the inside which eliminates all risks of damaging rails using the above-mentioned methods.
MM.
I would not recommend doing this as then you would see the holes from the playfield sides. They can be seen on EMs.
