Unfortunately not. It is very intensive on our database to roll back a character to the state before they accepted their class.
If you want to try a new class, you can purchase a new character in our Support Us! section.
Another alternative would be to get in contact with a moderator and ask them to ban your account. If you’re still in the early stages of Forumwarz and had a change of heart, they may oblige. Then you could sign up for a new one.