Uniwell NX 5400-F - How to edit text on recepit (Store name, phone number)?

I haven't worked with the NX5400 and 5400F as they are quite rare in most areas, so sorry I can't be of more help, but C-tech has a manual here if you get stuck:

http://the-checkout-tech.com/manuals/cashregisters/Uniwell_NX-5400_type_01_programming_manual.html

Registerman
February 2011