What are the steps for Xbox all access buyers?

I am currently paying a monthly amount for xbox all access, I found a deal before christmas to get the ball rolling and from what I know its going fine. When I started I got sent a new xbox one x like it said I would but now its coming to a point where
the new xbox series x will be coming out and Im not entirely sure of the process. I have gone through Smyth toys as the company providing the xbox series x and I know at some point I have to give the xbox they sent me back. But Ive had no emails or anything
about how it works and how I go about making sure I get the series x that Ive paid monthly for. Any help letting me know what Ill need to do? Thanks.

:)