If you have to remove any paint before staining the piece ... As for how to change stain color on wood, it is easier to add a darker stain over a light one than the opposite.
If you plan to keep furniture in front of the area and like having wood paneling, you could just paint the stained area and use a faux painting technique of lightly brushing on a lighter or darker ...
to instantly reveal All of the decking paint and decking stain is applied to pieces of decking according to the manufacturers instructions and then left exposed to the elements over the winter ...