Then you have to recreate it.
Here's how you can do this:
1. You go to the Details page of your contact.
2. Click in the right on the name of the Contact person.
3. In the Customer contact form you can reset his password by resending the activation mail again.
4. An activation mail is sent automatically to the email address of your contact.
5. If the customer clicks on the link to set his password he will be forwarded to the VIP Online Portal where he can set his password.
6. After he has chosen his password, he can log in with his email address and password.