When a user forgets their password, typically they can take care of that themselves by clicking "forgot password". This will start the password reset process and the user will receive an email with instructions for creating a new password.
But, if the email address in Conservis can no longer be accessed (or was never added in the first place), then the grower admin for the farm can help.
To reset a user's password, it is as simple as finding that user in your setup and creating a new username and password for them.
Go to Production (or Harvest) - SETUP - Users
Here you will see a list of users. Find the user you need to reset, and select the Edit icon next to their record.
Create a new password for that user and confirm the new password in the "Confirm Password" field.
Scroll down and hit save
Let your user know their new password
TIP: While you are in the record, now is a great time to update their username, add a working email address, and confirm that they are setup with the correct roles and time zone.