I also needed to get the Valerie modem in bridge mode ( or modem mode) so I can get WAN IP address on my Asus Router and continue using my own personal VPN server on Asus Router.
It seems the Modem itself is locked down with basic setup and doesn't have the Bridge mode. What I did to overcome the problem:
a) Connected my ASUS router's WAN port to one of the LAN ports of the Valerie modem.
B) Turned off all WiFi signals on Valerie modem ( to use my Asus Wifi Signal. You don't have to this step if you want to use Valerie's Wifi signal)
C) On my Asus router, under WAN configuration, selected PPPoE , entered my V2 username and password, and boom. It authenticated and got the WAN IP address ( No double NAT) and my VPN server on the Asus Router also works.
I read some people changed the credential on Valerie to something invalid before doing step C above. However I found it un-necessary as it seems Virigin ( Bell) allows multiple login to their network.
Hope this helps.