Using premiere pro:
1.
Change the blending of layers from Normal to Screen or Overlay in Blending modes. This will lessen the opacity of the clip so it's not the best way to remove black from videos. Only use this method for stills and graphics with good solid colors and a good contrast.
2.
Use the Color key and set tolerance and play with feather or better, use the Linear Color Key in After Effects
3.
In After Effects, throw in the Alpha From Lightness effect Or Demult by Hitfilm or Unmult effects from Red Giant
4.
Put the Set Matte effect, set the matte to Luminance, and add Gamma Correction to brighten the shot up.
5.
Add the Shift Channels Effect in After Effects and take the Alpha From Luminance. Tweak color values as needed.
6.
BCC Two way Key from BorisFX
7.
In After Effects, use the Extract effect