You don't open the DLL file. I would recommend using Extreme Injector v3 (Google it and it will be the first search), then add the lobby tool DLL. Then, launch the game, tab back to the Extreme Injector. At the process name, select iw2mp.exe (or just type it there) and press inject! Then you're all set.
I checked this out and I love this lobby tool.. only that when i change the game mode it fucks up in game.. E.X. I launch the game after changing TDM to Domination and it has white flags.. half the people are spectators.. and its just really fucked up.. the spectators cant change their team but are spawned in and cant be killed or kill. PLS fix..
How does one get other features for injectors such as custom text across the screen, the level 70 thing for everyone in the lobby, etc? I see these GSC things but not sure how they work... Thanks for any help.