I have super thick solid tree trunk thighs... but I want slender thin flower stems! (Photo)

 Changing the overall character of your thighs  is going to be tough. Weight loss would help, and there may be a role for some liposuction/liposculpture. "Thin flower stems" would require extensive skin and fat removal and you should think about that long and hard  after you have consulted with a board-certified plastic surgeon with extensive experience doing major post-weight loss procedures. Best of luck to you. 

Thank you for the photos. Though they do not tell the whole story, they do suggest that you could benefit from liposculpture. The key is the artistry of your surgeon, and your expectations.  See a board-certified plastic surgeon who does a ton of Lipo-sculpture and operates at a certified facility, and you will be in good hands. Do not shy away from asking; how many thighs, like mine, have you sculpted? Do not settle for a vague answer, then ask to speak to a patient who had a similar procedure. Do your homework, see more than one plastic surgeon, and good luck. 

Your thighs would have to be evaluated in person to determine if you have enough subcutaneous fat for liposuction to be effective.