I worked this little guitar arrangement of When You Wish Upon a Star for my friends son a few years ago. It's not too difficult if you have some experience, but there are a few stretches and techniques you may need to practice.
This is also a good example of how different jazz guitarists think versus most rock and pop players. Notice there are no bar chords and voices lead in a logical way.
I plan on doing some more lessons on chord melody, so if you have any comments or suggestions, please leave a comment.