I changed my password to something difficult to memorise which was stored in an online password vault. The result was it took an extra 20 seconds to login, which proved to be a very effective way to stop using facebook.
I just deleted the bookmark for Facebook so I have to type it in. Well, type "Fa" anyway. But just doing that instead of having a button to click cut down my usage by 70-80%. I was clicking the button out of boredom a lot, I guess.
I rarely use Facebook on my phone, I don't like the interface at all. Mostly I'll just use it to share a pic, and even then I'm going through Instagram to do it.
You need a compelling reason- a strong push or pull. Otherwise you're overcommitted in your current position. The in-between is a very distressing place to be. Decide on one or the other and commit to it wholeheartedly. You can always return and take the other path later. :)
I never do it.