ok. so the mod that i want to use is this particular mod in the video (the 'heavy vehicle), but the problem is that i have never used mods on gta4 before, and i really need some help with that

where do you download mods, and how do you use them? i don't even know what these mod files are like.... do you have to put these mod files into a certain folder or something? or is there some kind of a "mod-activating" software i need to download?

sorry for so many questions, but i'm really a beginner at this mod thing so pls help me!! T.T