Help! Fuel Lines and Rear Seat

On my 206 There are just the 2 pins that push thru the carpet down into an aluminum bracket over the stringers, push pins are at the rear, almost under the rear seat-back vinyl.
If you in fact pulled both pins just wiggle that seat base back and forth a bit, may have never been out so is just glued in place with gunk

To remove the rear seat back on my 2006 216 you must access and remove several bolts with large black plastic in knobs though the rear storage compartment. Open the rear compartment and remove the carpeted trim panels. You will then see the bolts/knobs spaced across the top portion on the rear seat back. You will also likely have to reach your hand around and under the gunwale to access the bolts securing the curved side portion of the seat back. After removing the seat back you will be able to easily pull the pins holding the bottom seat base in place.

Your boat may be more similar to the older design. On my 1998 176 there was one lock nut that retained each of short curved side portions of the seat back to the side of the boat. The nut had to be removed first (the bolt was fixed to the seat) then the side portion of the seat had to flexed toward to center of the boat to pull the bolt though the hole. Once that was done the seat back lifted straight up and off of the mounting brackets that were located along the main portion of the seat back. I hope this helps.