The front seems to be clipped in towards the middle, over the "transmission tunnel", together with the wiring. I did try to lift it from the back, but was worried how much I was twisting the seat...
I have had the rear seat out in my 2018 Leaf. All you have to do is grab under the front of the seat and lift up. You need to make sure you grab near where the clips hold the seat down so the seat doesn’t twist.
I had the rear seat out on my 2012 Leaf several times - when water flooded the car, to install Wet Okole Seat Covers https://www.wetokole.com and to deep clean later. Mine were easy to take out by lifting and pushing towards the rear of the car to make them come unclipped. My car has the heated rear seats and there is enough wire underneath for you to lift before detaching the wires afterwards. I would suggest looking at Youtube for videos.