Message an admin though a personal message on the forum, or message them on discord (Anyone with a red name). State the name that you want and send THAT SAME ADMIN YOU MESSAGED the 100,000 credits. If you are going to send a PM through the forum, title the message to something appropriate, like, "I Want a Name Change".

Doing what I said above will start the process of the name change. Afterwards, you'll just have to wait for whichever admin you chose to be online and do it. If you have anymore questions, feel free to post here. You can alternatively message me on discord or though private message on the forum.

I hope you learned everything you were looking for.