What should I do to make my neck and chin look more like the picture on the right? (photos)

I must say that I object to your original premise that something needs to be done here.  You have a nice profile and there is nothing that needs to be changed at all.That said, there are options to get the "Giraffe" neck you seem to want - I would just not be willing to do it for you.  It would involved removal of the deep fat deep to the platysma as well as division of the platysma at the apex of the angle of your neck.  I have done it on only one occasion and will leave a link below.

Thank you for your question.Chin liposuction is not going to accomplish what you want.  Either a chin implant or formal genioplasty by cutting and advancing the bone is necessary to accomplish the picture on the right.

To be sure, see two or more experienced,
board-certified Plastic Surgeons for a complete evaluation to make sure you are
a good candidate and that it is safe for you to have surgery.

I hope this helps.