Huy137 I checked with the Spine team to see if there might be any other solution, but unfortunately the kind of copy and paste you're looking for is not currently possible. Since there are no backup files from before the texture was overridden, it seems the only remaining option is to manually reconfigure the mesh.
When the size of an image referenced by a mesh changes, Spine should display a confirmation dialog warning that the mesh may be affected. In the future, please make sure to carefully review that dialog before proceeding, especially when replacing textures that are already being used by meshes.