Use GM multipurpose powdered cleaner GM P/N 1052925 or equivalent for this type of cleaning and when you clean panel sections where small cleaning rings may be left from spot cleaning.
Vacuum and brush the area in order to remove any loose dirt that surrounds the trim along the switch or welt lines.
Clean the complete trim panel one section at a time. Follow the directions on the container in order to mix the cleaner. Use suds on a clean sponge. Do not saturate the material or rub the material harshly. Wipe off the remaining residue with a slightly damp absorbent towel or cloth. A heat dryer or a heat lamp may be used. Use caution with a heat dryer or a lamp in order to prevent fabric damage.