This video shows a top faceboard with plastic clips that hold the headboard on.
Often the headboards will be velcroed on or sometimes have double sided tape.
With double sided tape the tape often goes hard with the heat so be careful removing the headboard. Use a flat knife to ease it off the head rail. Just slip the knife between the head board and the tape and slice the tape of the head board.
Another model (Weathermaster or NZ Window Shades), has metal clips and the head board will clip off.
Mark the position of the clips once you remove the head board for easy return of the head board. Sometimes the tiny screws that hold the brackets on pull out. If so you can replace the brackets with Velcro.