Steps of replacing a window regulator switch:

1. Open the door where the window regulator switch needs to be replaced, and locate the gap at the joint of the trim panel and the door panel;

2. Insert the prepared tool into the gap and pry up the trim panel. Take out the trim panel along the gap;

3. Hold up the trim panel and remove the plug of the window regulator switch;

4. Turn the trim panel upside down. Loosen the small fixing screws of the switch, and take down the lifter switch;

5. Install a new window regulator. Tighten the screws and insert the plug;

6. Test the lifting function, and re-install the trim panel after confirming normal function of the switch.

Possible reasons for unsmooth window regulator:

1. Aged glass rubber or dust accumulation;

2. Too much dirt or presence of foreign matters in the glass guide slot;

3. Failure of a glass lifter component.