Help with Plex

I have a base Roamio with a wired ethernet connection.

I have an Android phone.

I want to stream a video from the phone to the Tivo.

I THINK using Plex.

I've been messing around with it now for a couple of hours and can't seem to figure this out.

Can someone either give me a basic on how I could do this, OR, point me to a tutorial on how I can do it?

Thanks!