Is it illegal in GA to change the spelling of your first name just because you so desire?

To legally change it
It costs approximately $25. To $149.

This is a reputable site.

Legalzoom.com makes changing your name easy

Georgia Name Change Forms and Name Change Law

You could also change it at a vital statistics office probably in your State Building or City-County Building

Remember you would also have to notify social security and change it on your drivers license.

Yes, name changes in GA is easy to do, I would check out your county court, I believe they furnish a form and you merely file it. There is even a family filing, so ifyou have several members of your fmaily wanting to change their last name.