I had to replace one of mine after a passenger had put their heel into it.
Trim removal tool to prise away the plastic trim at the bottom of the door entrance. Move carpet and gain access to unclip the electrical ribbon connection - the connection inboard and positioned at the centre of the sill plate.
The sill plate is bonded to the body using double sided tape. I heated the area to soften the glue prior to prising with a trim removal tool. However, the aluminium plate is very flimsy an I would expect you to bend it and/or distort/dent whilst trying to remove, no matter how carefully you try to remove this.