You have to buy one of the baths from the furniture shop ( Using bearbills not credits) and put it in your cub condo then click on the bear and click on the bear head that has the bath icon and...
You can't get your Build-A-Bear out of your backpack when you are walking around Build-A-Bearville, you can only change the furry friend in the backpack. But Your furry friend does come out of its'...