Take the battery charger out of the cardboard box and connect it to the power supply in a dry room (not in the bathroom).
Take the backrest unit out of the cardboard box and unbutton the cover at the top rear side .
Hold down the case of the control unit in the drawer module .
Seize the battery in the grip recess and pull it out of the drawer module .
Remove plastic transport protection (connection breaker between the battery and the case of the control unit) .
Place the battery on to the battery charger.

Take the seat unit out of the cardboard box . NOTE! When lifting up the seat unit, the scissor mechanism opens. Do not jam your fingers in the scissor mechanism when putting the seat unit down !!!
Place the seat unit on the clean dry bottom of the bathtub, the recess for the assembly of the backrest facing the head end of the tub.
Press slightly on the seat, so that the suction cups adhere firmly to the bottom of the tub.
For the assembly of the backrest unfold both side flaps and lean them against the side panel of the tub .
Seize the backrest at the neck support and in the curvature at the lower edge .
Insert the lower end of the shaft with the two round, green guide pins vertically into the forked recesses of the baseplate .
Let the guide pins lock down into the fork and press from the front slightly against the neck support, until the backrest locks.

Remove the charged battery from the charger and slide it into the drawer module of the backrest. The label of the battery must face the front.
With light pressure, bypass the stop point and push the battery until the curvatures of the battery case and the neck support are congruent.
Pull the cover of the backrest tightly over the curvature of the neck support and close the push buttons.

Test run !!