Do you have downloaded, or are you having trouble finding Part 1 ?
Here is a quick guide on how to correctly extract and install it: 1. Gather All Parts paradise_lust_win64_0.20.0a.part2.rar
If the archive asks for a password, check the site where you downloaded it; common passwords for game archives are often the name of the site or the uploader. Do you have downloaded, or are you having