Need help setting up a LS300

Hi, We have a bunch of LS300’s and I have a Cisco RV042 VPN Router that I want to setup to use as a VPN connection to the main office. How do I go about to setup the LS300 as just a modem and use another router. Sorry if I’m not clear with my question. Thanks!

Are you looking to pass the IP address that you are receiving for your carrier directly through the LS300 to the Cisco router? Or are you looking to use the VPN function in the LS300 to setup a tunnel to the Cisco router?