why arent mods working?

alright so downloaded a mod of this website and then used rezinject to inject all the rights files to the right places, is there something else i need to do

Did you remove the original rez file rename the new extension from reznew to rez and did you boot the game from combatarms_direct or the website

i always load the game from the website and use cheeta injector and it never seems to work can someone please help me?