Enter the requesters email address, press "Send reset password email"
If you get a success message, the email has been sent
If you get a failed message, the email hasn't been sent. This is usually because it's not the email address we hold for the farmer - so ask what email address they signed up to the scheme with.
Once you've sent the email successfully there's a macro in ZenDesk called "Resent password reset email". That will fill in a lot of fields for you, along with a message.