Answer:
Step-by-step explanation:
The best thing to do in this situation would be to explain to your client why your design is the best fit for what is needed and give them detailed technical reasons. If this still does not convince them, then give them a step-by-step explanation/demonstration as to how the quality of the work will be decreased if the changes are made. If this still does not change their mind, then you will need to make the changes and deliver the adjusted work as requested by the client since they are the one that is paying.