And with an 18 mo I'd do step one and then skip to step 3 and make step 4 doing it with him or even 4 him, though if you start and make it playful he will likely jump right in
And I'd encourage you to do the Bear Hug at neutral and positive times--usually I just brush into a room, grab someone up in a Bear Hug, and then go back to what I was doing. This way my children don't associate it with conflict, but with comfort
hth