Have you tried using “view hidden geometry?” You can cut the trunk, lower the tree and work on the outline. Also there is extra uselesss (AFIK) geometry. You just need the outline of the tree with the texture.
Make hidden geometry visible. Using Tools On Surface plugin might be the fastest way to draw a new outline. HIde the new outline edges. Remove the rectangle and the extra outline object, whatever that is. Edit the component from the component window and set the shadow to follow the sun.