Steps:
- Open a new project and place footage onto the timeline, ensure the footage is placed on video 2.
- Select background picture and import it into Premiere Pro and put it onto video 1’s line.
- Then move onto clicking effects, keying and ultra key which has to be dragged onto video 2.
- After that, it is likely the background is too small for the video, to fix this you have to right click video 1 and choose the option ‘scale to frame size’
- If the green screen has marks on it then you must get rid of them by double clicking the video 2 and select ‘effects control’ and choose the option ‘aggressive’.
- Finally, the green screen should have disappeared and you have a background.