Head to this website to download the script
http://punbb.informer.com/downloads.php
Next login to 000webhost.com
Open up your site, then file manager and begin to upload
Once uploaded visit http://yoursite.000webhostapp.com/unzipper.php
Unzip the script onto your hosting
Now visit http://yoursite.000webhostapp.com/punbb-1.4.4/admin/install.php in your browser and leave it open
Open 000webhost.com again and this time hit manage databases
Create a new database for your forum
Once created take this information and put it into the install.php you’ve open
Choose your administrator login details
Now your forum should be installed
Ta-da!
Make sure to use the settings you need to get your forum customized.