How to continue playing the old saves in the latest build

Hello Parents,

For those who ask how to continue playing with your old saves (version number 1.0.9.7) in the latest build (version no. 2.0.0.3). And what's the major diffences between these versions. Please refer to the below accouncement. https://steamcommunity.com/games/736190/announcements/detail/3177861894981976633