If your tree is still usable, offer it to friends or donate it to a charity such as Goodwill or Treasures from the Heart.
Treasures From the Heart 200 S Main Street River Falls, WI 715-425-9771
Treasures From the Heart 815 Main Street Baldwin, WI 715-684-2545
If the tree is no longer usable then it will have to be thrown away, check with your hauler to see if they will accept it in one piece. If not, it will have to be dismantled into smaller pieces and put in the trash.
Many municipalities have curbside Christmas tree pick-up for a short time period after New Year's.