In my scenario, humans have advanced to the point to where they are god-like machines barely recognizable to the humans of today. With the appearance of their bodies being the only thing that is similar. (And even then, the new human bodies can be quite different due to augmentation.)
They are capable of living for as long as they have sufficient energy and they can manipulate their virtual and physical home world's at will. They also tend to expand by converting planets into giant quantum computers and building Dyson swarms around lonely stars.
And despite being fairly secular in view, they are also quite spiritual, as they view themselves as higher celestial beings for having passed the Great Filter. And in the stories setting they are the first and only species to have ever evolved to sail the stars.
This spirituality has led post-humanity onto a quest of uplifting and analoging any and all life that they come across in order to ease what they see as the innate suffering of the flesh.
Now that the background and setting are filled out, I can get to the core of my question, which is how would an advance human society such as this integrate a lesser one like ours?
And since I'm often told to be more specific (and because I think it's more interesting), I would like to use our present day Earth as the basis for the society that is being integrated into the post-human one.
Things to consider: (if this part broadens it too much then please ignore)
How would the differing and sometimes warring states be dealt with during and post-integration? What about prejudices such as racism?
Would the advance civilization use spies to ease them into it or just show up and rip it off like a bandaid?
It should also be noted that post-humanity wants the integration to be the least stressful and painful for the integrating species as possible. People are also not forced into being integrated. It's more of a strongly encouraged offer.