Its quite easy...
First remove the plastic side covers, one small torx bolt each at the back, the right one (left one for you I suppose) is a bit tricky because its at an angle and a normal screwdriver wont fit. Then theres two nuts on the door side of the car and three on the handbrake side (for these I would recommend to remove the handbrake plastic cover, jerk it off), then just pull up the seat, which is quite heavy, about 20kg.
Remember to unplug the airbag and pretensioner cables under the seat, theres a yellow and grey one where you just slide the yellow thingy with a flat screwdriver and it will unplug. then theres the black and red one, you have to lift the red thingy but just a bit, not all the way. And unplug. Its better if you detach them from the seat. You also have to disconnect the cable to move the seat forward, its on the door side.
Hope it helps,
I also reduced weight by removing the door panels, which weigh 5kg each. It definetly goes faster but i felt steering was lighter and was not as confident in the turns. I weighed 110kg shed off.