HBO Max via AT&T

I have a similar question. I think I'm double paying (subscribe to HBO on DirecTV, so paying per-month, but my AT&T cell phone plan includes HBO Max).

So I'd like to unsubscribe to HBO on my DirecTV plan, but hopefully restore it back (at least the basic HMO channels) via the HBO Max subscription that I get through my AT&T Wireless Cell plan. 

1) Is this possible? Sounds like yes from the above, and
2) I cancel the HBO on my DirecTV subscription, what do I need to do to get the HBO channels back, through my AT&T Wireless HBOMax plan?