Step 3:

Select the body mesh (Skin Base) for the Texture (Skin) that you want to be Downtown Buyable. Click the small arrow to the right to scroll down through the list to find the right mesh. You can click down through them and let the textures load to find the right one. Here I chose an outfit that would be appropriate for Pajamas. This particular outfit was created by Callisto quite some time ago over at http://welldressedsim.com.