I have found a very nice Tutorial for installation of phpBB3 for any domain.

phpBB is a free flat-forum bulletin board software solution that can be used to stay in touch with a group of people or can power your entire website.

phpBB3 installation include two parts
A) Database configuration.
B) phpBB3 installation.

A) Database configuration.
Login to control panel like Cpanel, Plesk etc. (or any other mysql client) and perform following actions:

1) Create Database
2) Create Database username
3) Database Password
4) Grant Proper Permissions to the users

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