I tried looking into this over a month back, and I found a work-around. Basically you download the version from this thread and replace the steam files. You should be able to find the files by pathing through your windows file explorer directory: Local Disk > Program Files (x86) > Steam > steamapps > common > SiNiSistar
If you have saves you want to keep in your SaveData, copy the files and add them back in when you're done replacing. I haven't tried this myself, but it should keep your save data intact. If not, then you'll have to start over without the save data. If you see the title screen without "Lite version", then things should work out fine.