i want to gain any level i like, sooooo:
1) i know where to download it, but will i need any fix packs, patches etc, to make it work?
2) do i just install like any other patch yeah?

1)I wouldn't think so.
2)Instructions about how to install it will probably come in a readme file with it.

I dont know of any xp cap remover that requires patches. Most xp cap removers will instruct you to install its files in the Baldurs Gate 2 overide directory

The XP cap remover does not require any patches: it extends the internal tables of levels, resistances, hit points and spellbook capacities. That's all. It can clash with those patches that do the same. If you have some such patch installed then check the names of the files in the XP cap remover zip file and decide whether to install the remover if you find file names already present in your "override" directory.
Note: The remover contains the weapprof.2da file. The same file has been installed by the game itself. Because the original file is installed from a CD, it is read-only. Either remove the read-only flag of the original file or "skip" the weapprof.2da file during installing the remover. As far as the remover from TeamBG is concerned, both weapprof.2da files are the same.