For the Sportscraft ones indeed you need the handbrake lowered, and as rod_vw pointed out it's better to lower the bracket that's on the seat base already (drill out the spot welds, pry it off, weld it back on, spray paint.
For swiveling, if you want to swivel with the seats in the lower position you have to do some trimming of the plastic sides of the seat, because they will catch on the swivel otherwise...