Linksys wrt1900ac internet help

[Harinder]

So my current modem is this one (pictures):

1: http://gyazo.com/a79c8af55cd2194202ab2a7241014832

2: http://gyazo.com/63609c510f33f0fa869af73433ec4802

3: http://gyazo.com/9fb72c947740539afde9010bd732ee31

 

I dont want to rent this modem anymore, so I am looking for a crazy fast replacement. I found the Linksys wrt1900ac, but I saw that it didnt have a 'Tv cable' like input on it, but only had a ethernet input. How can I replace my current Xfinity modem with the Linksys wrt1900ac, or is there a better solution to this.

 

Do I use some kind of converter?

[Excon]

You still need your modem, You just run an ethernet cable from your modem into the Linksys router

[xmx1024]

Tell comcast to put your modem in "Bridged" mode, after they set it to bridged mode the lights will flash and eventually the wifi light will turn off. Then plug the 1900AC into ethernet port "1" of the gateway. If you get no internet access after that process, reboot the gateway. If that does not fix the problem, connect directly to port 1. The modem may want to be re-activated.

 

Source: Experience.