Do not do this modification and drive around with the seat reclined right back.
This is about the maximum that the back will move to as standard. Ain't no one sleeping in that.
You have to get to the back underside of the seat so it's easier to remove the seat.
The reason that the back stops reclining where it does is because of this tab (arrowed).
It has to come off so grab your Dremel with a cutting wheel.
Cut it off and tidy it up with a grinding wheel.
Once you have cut that off, the seat can now be reclined much much further,
When fitted to the car, you'll be able to recline it back about this far.
The thing that stops it moving is the seatbelt guide hitting the boot side interior trim.
Take the interior side trims out and you can recline most of the way into the boot.
But out of the car, it can be reclined all the way back to the floor.
What ever it is, the seat is limited in the forward motion too but that can be overcome in the same way
I can't think of a single reason why you'd want to fold the driver's seat all the way forwards however...
Cut the front tab out with a Dremel and tidy it with a grinding wheel.
Now you can wind the seat back so far forwards you'll be driving like an old woman.