This is the info I received from Humax Towers a moment ago, re my earlier post and your query.
1. Product is at least 10 years old.
2. Check they have the RS-101P remote
3. The sequence you gave them is correct
a. Make sure they are in the STB STATUS menu (with the h/w, s/w details, etc)
b. Make sure they press each button firmly (RED, GREEN, YELLOW, BLUE, WHITE, 0) – WHITE is the timer button and it is the number 0
After the above the message “PIN Code is reset <OK>” should appear.