Hi,
You can try this site. Download the program, pay $9.99 (click on RESET KEY bottom left of page) for how to pay for key to make program work.
http://www.wic.support/?page_id=134
'''They also offer a free Trial Key (it only reduces your counter down to 90%) to get you going more quickly'''
http://www.wic.support/?p=198
if you look closely at the video in the middle of the page they type the word, '''trial''', in the box for the key
This one program is only one of many, just for your info, you may wish to find one that you prefer by googling reset waste counter Epson L120