Fill in your e-mail address which you used at registration and click on "Send new password". On the given e-mail address you will receive a verification link. Validity of this verification link is 2 hours. Click on this link and you will be redirected to a web page where you can create your new password.
This procedure is necessary for security reasons of your account to avoid unauthorized change of your password. Saved passwords are encrypted. Not even e-shop administrators can detect it and send it to you. This is the only possibility how to renew access to your e-shop account.