Dan, just to confirm, there are three account levels in your eez.io store.
Your eez.io store account levels are: store owner, store admin and customer. - Your question is about reseting password of store admin account.
For security reasons there is no built in way to reset store admin account as reseting your store admin account will also reset your admin permissions.
If you are not able to login to your store admin account, and need to reset your password, please contact the owner of the store you want to reset your password for and ask him/her to delete and than recreate your admin account.
Once that is done you will receive a new invitation link where you will be able to enter new password for your new account.
Please let me know if you need any farther assistance.
Steve - eez.io support