If you want to actually change the name of the corporation, then you'd have to check with an attorney about the rules in your state. Details are different for different states.
As to how you do it, your first step is to contact a local attorney with small business experience. It shouldn't be expensive -- this is bread and butter for a small business attorney.
Al Lautenslager is an award-winning marketing and PR consultant and direct-mail promotion specialist. He's also the principle of Market For Profits, a Chicago-based marketing consulting firm. His two latest books, Guerrilla Marketing in 30 Days and The Ultimate Guide to Direct Marketing are available at www.entrepreneurpress.com.