I can't find the video that I saw previously, but it doesn't appear to be very difficult.
Behind the radio, there is a piece of plastic that can be popped out using a plastic interior trim removal tool, or if you're braver than I am a small screwdriver. Once this piece is off, there are four bolts; I seem to think they're 10mm. Remove these four bolts, and you should be able to pull the radio towards you, allowing the disconnection of all the wires.
The video that I saw stated that the '20 Rav4 has the same setup. Perhaps doing a Google search for that might help.