Disconnect the bottom of the horizontal blinds from the hold-down brackets, if your blinds use them. Shift the bottom bar left or right to disengage the bottom bar from the bottom bracket pins. Remove the screws securing the bottom brackets to the wall with a Phillips-head screwdriver.
Open the slats to the open position with the wand. Open the horizontal blind completely, using the pull rope to raise the blinds to the head rail. Grasp the valance from above and below on both ends with your fingers. The valance is the decorative cover that hides the head rail. Press in on the top of the valance and pull it away from the blinds.The bottom of the valance will disengage and you can remove it completely from the blinds.
Unsnap the valance clips off each end of the head rail as well as at each ladder on the head rail. The ladders are the strings that run vertical and hold the slats separate from each other.
Slide the front caps off each end bracket with your thumbs. Grab the horizontal blind head rail with your hands and pull it out of the brackets. Some horizontal blinds also have a center bracket. You may need to lift up on the center of the head rail to disengage the head rail from the bracket.
Remove the screws securing the end brackets and center bracket from the wall with a Phillips-head screwdriver.