I don’t know any book specifically for transitioning from OpenGL 2 to modern OpenGL. But I think if you already know old OpenGL well, you just need to learn modern OpenGL and then you can figure out how to rewrite things.
And as for modern OpenGL resources, for me the OpenGL Wiki website is a very good resource. It explains in simple terms a lot of things about modern OpenGL (mostly). Also, the official OpenGL Programming Guide book (edition 8 or 9) is good; it is just a bit harder to digest. And the API reference is essential. Either docs.gl or this is fine.