I assume you mean the company name that prints at the top of the customer receipt. You can change that by going to Program (PGM) mode, select LOGO DESC PROGRAM (number 7, I think) and then PREAMBLE. This is covered in the programming section of the manual under "Logo Programming". You will need the alpha overlay in order to type in the new name. This is shown on pg. 6 of the manual if you don't have one.
Good luck ...
Steve, December 2009