The rod under the seat
The bolts either side
The rod removed and the leather loop/flap lift up to reveal a second flap held in place with a row of bendy hooks
The second flap raised
the space visible
You can see the heater element with the wire hanging out. Use a couple of rulers to push the element down. The were a couple of nylon threads six inches down with I just cut. No harm done from that as far as I can see.
I hope that this helps
