You need to add text in the design model. I am assuming you have a sketch at the bottom of the tree, delete it and open up the design model and lay it out their then close it. For the toolpath, select profile toolpath if its simple on the surface and define geometery-click (multi-chain/add) then "text" check box. Mouse over until you see the big "A" and text is highlighted, click and you are good to go.
If you still have a problem post your file.