Many time I have been asked this question.
The solution is to contact the Payoneer support. The support will answer within 2-3 days and you can reset your Payoneer PIN
with their help.https://payoneer.custhelp.com/app/Contact_us/l_id/1
I have never lost my Payoneer PIN, so don't know how it works. But, without the support help you can't reset the pin.