Remove any of those sites from your bookmarks tab. Unsubscribe to any type of email from these places. Remove the relevant apps from your ipad, phone, whatever.
I had to do all of those things to wean myself from Facebook. Yes, I still get on it from time to time, but it has lost much of its appeal to me.
You will find that you suddenly have what feels like lots of idle time. I've recently re-discovered watching TV. We have Netflix and Amazon Prime, so there's always something to watch. Reading, of course, is good too, but I do more of that in bed. Sometimes, I even notice myself watching TV without having a laptop on my lap (which just makes room for my lapdog)! There's also cleaning, playing games, with the kids, etc.