They're not difficult really. Have a crack. The drivers one is a bit more of a fiddle than the passenger one but neither are that bad.

As I remember on the passenger one you just have to slide the runners back and forth so you can get at the bolts that are actually hidden inside the runners front and back.

On the drivers side you have to unbolt the front height adjuster bar from the rest of the frame by undoing the two bolts that go in through the sides of it, and the back of the frame has two similar bolts. Then remove the adjuster bar from the seat.