You will need your programming sheet. If you don't have one, the book will show you the layout so you can make one yourself. Follow the flow chart for PLU programming using the start, select and designate buttons on the programming sheet. Once you enter the new information, use the enter key to save. If you have lost your manual, one of the users has it listed. Don't worry about the different model numbers, it covers the MP2. See here:
http://the-checkout-tech.com/manuals/cashregisters/Towa_ET-7626_and_MR1_programming_manual.html
Registerman, November 2013
