It's not hard if you have the right tools for the job, it's just time consuming. Some of the screws you'll need to take out (like for the visors and the Oh Shit handle, maybe more) are Torx heads, but they'll come out with the right size flat head screwdriver. I got my liner out through the passenger side door. You can't get it out through the driver's side cuz the steering wheel will be in the way.
That liner has some weight to it, and it won't be long before your arms and shoulders will be on fire trying to maneuver it out of the car by yourself without bending it. If you can, get someone to help you hold it up as you remove the final items and it starts to fall on you, lol.