This page explains the procedure to update firmware for products that have a VE.Can port. There are two ways:
Updating the firmware of a VE.Can product is typically most convenient by using the remote option. Its then not necessary to obtain the CANUSB adapter. In case you do need, but don't have the CANUSB, contact your dealer; they'll be able to help you in most cases; by lending one or by doing the update for you if you send them the product.