[MovedGoalPosts]

Please remember that not everyone understands naming descriptions for IT stuff.

For the benefit of the OP and others:

The modem is the device connected direct to the internet service. Keeping things simple it provides the authentication of the customer's service with the internet service provider (ISP) i.e. Virgin Media), and allows data to enter or leave the ISP's network. A modem can normally only communicate with a single customer device, i.e. one computer.

A router is a device that will create a network for the customer (there are also routing devices all around ISPs and the internet, but we can ignore those for now). The router will sit between a modem and the various computers or other internet enabled devices (smart TV's, games consoles), of the customer. A router acts as an intelligent junction box in the customer's house allowing data to be sent between the customer's own devices, and also allowing devices to receive or send stuff from the internet. The modem will only see the router as it's single connected device. It is the router that enables the multiple device connections. Routers can be wired only (for ethernet lead connections) or can also be wireless enabled. Alternatively you might choose to place a wireless access point on one of the wired connections to the router to achieve a similar result.

On a Virgin Media network, only the modem provided by Virgin Media as part of the customer subscription, can be used. Customers cannot use their own modem as that is against the terms of use of their contract with VM. Chances are it could not be configured to work and Cable Forum would not assist anyone trying to do this.

The Superhub used by Virgin Media is a combined modem and wireless enabled router. The router functions of the Superhub can in many cases be disabled leaving the hub in modem only mode so customers can provide their own router.

In most cases, on adsl type internet services (BT phone based), customers can provide their own modem device. In many cases the ADSL providers are also offering their equivalent of the superhub.

If you wish to provide your own routing device, to replace the wireless functions of your Apple Time Capsule, then simply power down the modem (if a superhub change it to modem only mode, and power down) connect your chosen router's WAN (internet) side wired port to the modem (or superhub) LAN port, using an ethernet cable, power up the modem and then router. The configuration stuff of the internet connection should have taken place automagically leaving you to then configure your chosen wireless on your new roouter.