Actually it is not difficult.Learning to be present in all its comfort and discomfort is a difficult but vital practice for us addicts.
It's just that we're not practiced doing that, since we've been "away" for so long.
When the option of being away is not desired anymore, the eyes slowly but surely start to see all the good here that we've been ignoring for so long.
And because the good is real and near, we get to experience it immediately and continuously, unlike self generated illusions.
As you have correctly mentioned, to be present at all times and unjudgementally accept both the good and the bad.
I would also like, to constantly give encouragement and support to ourselves like we are our best friend and believer.