- Copy FunctionList.dll into
<notepad++ install dir>/plugins

- Copy Gmod Lua.bmp and C++.flb into
<notepad++ install dir>/plugins/config

- Copy FunctionListRules.xml into

Vista / Win7
C:\Users\UserName\AppData\Roaming\Notepad++\plugins\config\

Vorgabe:
%APPDATA%/Notepad++/plugins/config 
or if you didn't install with %APPDATA% <notepad++ install dir>/plugins/config
