BBcodeing troubles

Hey all.
I recently set up a forum Here. But i'm having problems, I'm trying to install GWBBCode on it.
Now i have searched everywhere looking for any advice but i cant find anything. Firstly is it even possible for me to add this to my forum? It says on the instructions that i need to modify files from the directory but i cant seem to do this? Maybe Support/Admin from here can only do it?

Here is the instructions to install GWBBcode to a forum.
Here is the original

Installation procedure
In the following, ~ will refer to your phpBB, PunBB or vBulletin forum directory (if you can't modify files from these directory, you won't be able to install gwBBCode). For PHP-Nuke, the forum directory is in the modules directory. Note that the pickup and SQL feature are only available on phpBB2 and 3.

1. Copy the content of this archive into ~/gwbbcode/ so that one can access ~/gwbbcode/install.php
2. Access ~/gwbbcode/install.php with your browser and follow the instructions (you may get errors because of access permissions).
3. If you want the skill database to be stored and accessed with MySQL (only possible on phpBB2&3), set GWBBCODE_SQL to true in ~/gwbbcode/config.inc.php and access ~/gwbbcode/install.php again.
4. If you want builds with Kurzick/Luxon skills to be adapted to your alliance faction, set GWBBCODE_ALLEGIANCE to 'Kurzick' or 'Luxon' in ~/gwbbcode/config.inc.php (Kurzick by default, so edit only if you are Luxon)
5. If you want builds with PvP/PvE skills to be adapted to the way you play, set GWBBCODE_GAMEPLAY to 'PvP' or 'PvE' in ~/gwbbcode/config.inc.php (PvP by default, so edit only if your builds are mostly PvE)
6. Then try example posts from ~/gwbbcode/examples/ especially the short guide ~gwbbcode/examples/howto.txt

I dont know if i am suppose to buy credits to be able to do this, i mean its no problem i just havent found anywhere that would suggest to me to do that.

Sorry if i missed something really obvious as this is the first forum i have made before.
Thanks in advance and any advice will be greatly appreciated.