Well, this is a really tricky thing to do. I should do a tutorial on it at some point. I’ve done many professional paint shots like this but they haven’t let me use the footage so let me walk you through the main points for a reflection remove.
So first, you have to remove the reflection from the scene entirely. For museum frames, that means replacing the image shot with a high rez pro photo of the actual artwork for best results. But you can use the remove module if you can see enough of the bg image through the reflections to get this done.
Next, you need a new reflection, an inverted and scaled up section of the footage can work sometimes, depending on the shot, or sometimes you need a whole new reflection to replace the reflection with. Whatever way you decide to replace it, you need to track the movement of the original reflection and apply that to the new reflection. Usually translation only is fine for this. You then need to isolate the reflection with roto and blend it properly back into the scene.
You can either put the reflection in as an insert with motion blur or you can comp it is as a corner pin or power pin depending on your host software preferences.
Please let me know if you have any questions and I will be happy to help you.