D156 Online Form - Correction first name

[jagadishrashmi]

Hello Forum reader - hope you can provide some directions
My uncle and aunt are planning on visiting the US and I filled their D156 forms.
As mentioned Q1-14 cannot be edited and it gets automatically filled - however we realized that the first name that gets auto-populated in misspelled.
1. How do I go about getting this corrected?
2. I have an appointment scheduled for Jun 29th - do I need to reschedule?
Also their visa was rejected on 214b a while ago and they are retrying. They have long planned this vacation and would like to visit the US along with their siblings (all 60+) to celebrate most of them turning 60.

Any inputs to increases their changes of getting visa will greatly help.
Thanks

[jagadishrashmi]

Corrections in Q1 - Q14 in DS156

Just FYI - here is the response I got from US consulate for errors and correction between Q1 and Q14.
There are two options:

Kindly note that the modifications on Q.No 1 to 14 cannot be made, either you need to cancel the appointment and schedule a new appointment or you could go ahead with your appointment and inform the consular officer of the same wherein the final decision would be that of the consular officer.

You can cancel your appointment only two times. After the second cancellation your HDFC Visa Fee Receipt is deactivated for 90 calendar days. You will not be able to book another appointment until the 90 days have passed.