The finish of my house has been done for years. But the protective film on the marble surface wasn't removed at that time. Now it gets difficult to remove. What I can do?

nan

Using lacquer thinner.

Apply some essential balm or detergent to the marble surface and cover the surface with preservative film. Press out the air between the surface and the film. And then tear off the film a minute later.

Apply some essential balm or detergent to the marble surface. Then cover it with preservative film and press out the air between the film and the surface. And then heat the film with electric hair drier to soften the film. When the film gets soft, tearing off the film.