Grab it from underneath the front of the back seat and exert a little pressure to jerk it up. It won't hurt the seat. The battery is located under the back seat. The seat goes back with no problem.
Your car is starting to overheat or your thermostat is going out. Get it checked.
Check the motor mounts. If rough when going from Park to reverse or even when in drive it's possible broken mount is the reason. Had same issue and replaced mounts and no more problems
If you have fixed the problem it should reset itself. If not, the light will stay on.