How to keep game when I want to change my phone.

Hello, I am playing Candy Crush Soda Saga on a Lumia smartphone. Now I want to change a new phone (maybe an Android phone). I search on Google but I found no official information about how doing this. I was playing offline and I never click on "Connect to Facebook". People tell me to do so, but on my Facebook account I am playing Candy Crush Soda Saga, too. In my Facebook my game is at level 12 and on my phone is at level 200. So I was wondering what would happen if I choose "Connect to the Facebook"? I know just 200 levels is a tiny progress but I don't want to replay any levels or I would change another game :"(

And when I have a new phone, what I have to do is install the game and click "Connect to FB'? Or I have to install Facebook, too? I am afraid of testing because I don't want to lost my game. 

Thanks for reading this ask. I hope someone reply me soon. Sorry for my bad writing English.

Have a nice day.

Hibari Kou