how to reset/clear the plugin data

i’d like to know how can I reset/clear all the data on Membership 2 Pro only?

A few days ago I had a test user called zak

he purchased a couple of memberships and all seemed to work ok. I later deleted the zak user.

i was testing again today, registered a new user called zak and the account page showed me the archived invoices and his membership purchase activity from the last series of tests i did.