1. Move the files you downloaded to one folder

2. In 7-zip or other extractor, open 'aokana_installer_v1.01_part1.zip'

3. Select Extract, and in this case, I chose to extract it to the same folder. 

4. Repeat step 2-3 for each file, dragging the file into the install folder. It should look like this when done (I renamed the folder, this is an optional step):

5. Click on Aokana Installer.exe. You may have to tell it to allow changes on this device.

6. Follow the prompts to install the game.