Hi! If you downloaded the game directly, you can just replace the files of the previous installation with the new version. Save files are stored elsewhere so they won't be overwritten by that. We hope that helps!
Thank you so muchh <3 <3 <3
Actually i might have deleted the old version and I've been trying to start the newer one (by just clicking open) and it won't work. please (try to) help ;-;
Are all the files of the new version downloaded? It might also work to delete the game files and just download the new version again (aside from save files the old version isn't really necessary for it to work)