What software should I use to replace an LED display in a train carriage? Look at this Video. Notice the text moving in LED and the reflection of it on the ceiling of the train. I also took a picture with blank LED screen.



I want to add my own text marquee-ing through the LED in the picture. Everything will be static as the photo except the text in the LED and its reflection.

What software, and what actions do I need to do to achieve this? Any tips and tricks please? I have a Macbook Pro i7. Freeware options are more preferable.
I would do this using after effects. You need to do a little bit of motion tracking as there is a tiny bit of motion on the camera as the train moves. Find a font that matches the LED display font on the screen. Carefully match all the colours you use using the eye dropper. Add blur and noise to your comps to better match the footage.
You can fake blurry reflections surprisingly well just by flipping a duplicate of your comp and blurring it. The biggest problem you will have is the swinging handle in the foreground, which you may need to rotoscope with the rotobrush to isolate.
You can see a similar effect (but without any foreground rotoscoping) I made at 26 seconds in here:
https://twitter.com/financialtimes/status/985923651676659713?s=21