Moving my game from 3.9 to 3.11.1

Continuing the discussion from Cocos2d-x v3.11 released!:

Hi guys i have started my game with older version 3.9 and left the game half way, after i cameback from overseas i found the new version 3.11.1 can i just delete the older version and continue with the newer version?

Sure you can do that. If you are using source replace the cocos2d folder. If you are using the pre-built libraries, compile new ones.