On PC or Mac, you can just override the new version in the folder of the old version then it should work.
i haven’t tried on Android, but maybe you just need to install new version, it will auto override old ver.
Can you import your saves from this demo into the downloadable version?
I don't know if the Renpy Web saves exporting work, but you can also hold Ctrl to skip the read section in the download version. The demo is fairly short anyway :D.
Okay, thank you!