Manually installing a DLL?

Recently I got back into playing MW2 after 2 years of not playing. As I come back and try to inject my old IWNet and wallhack dlls I notice the game crashes. I dug around and found a patched iw4mp.exe where it auto disables VAC on startup which fixes my IWNet problem so I can play around my ban again. I dug around some forums for some solutions and some people were saying you can't inject dlls anymore or mw2 crashes. So my question is if theres a way to manually install a dll to work in game or if there's a different method I could use in order to get wallhacks working.

you can inject dll's fine. Old dll hacks won't work because their offsets need to be updated for 1.211 v2.