It means to stack wood, or do something demeaning.
It means F*ck you too.
(Whorachelle) Do you wanna come to the van and do duster with me?
(Awesome guy) GO STACK MY WOOD
(Whorachelle) Hey all this shit happened this weekend! I screwed chris and like 3 other guys I don't know and they took my birth control and my dad locked me in the closet for 2 days..(Awesome Guy) I DUN CARE! STACK WOOD!