Just use the charging door for access . The seats are bolted in, so not hard to remove . Mind sharing what you’ll be doing? Good luck and keep us posted .
Iv invented a specific adapter that fits between a 3rd party 2-way long-range remote start system, and the Prius Prime. It's an electronic device that enhances the remote start feature set. It allows for full-take-over, in other words, no shut down on door open or brake press, just get into a remote started car and drive off. It also allows 2 remote start modes while still plugged in taking a charge at level 1 or level 2. My prototype has a simple manual switch to pick which of 3 modes: 1. normal not plugged in remote start 2. normal mode remote start while plugged in 3. factory remote start while plugged in, but using the 3rd party 2 way remote. I need to tap into the 120vac/240vac lines to install a small dc converter so while plugged in my device will automatically know what mode to use. each mode has advantages and disadvantages based on what works best for your situation. And yes, anti-car theft is still maintained while remote started, fully. My hopes are to sell the patent to an interested company after a demo that it really works. As far as I can tell, there is no other way to do these things with any other product.
The seat bottom cushions come out by basically just pulling straight up in the front. They are hooked on in the back. The seat backs have a few bolts. Not sure about the center console or platform under the seat, but it's probably obvious once you get the cushions out.