It's been a while since I've done it but I'll give it a shot from memory. You need to go to settings and check "allow developer console" then in game when you press ~ it brings up console commands. You need to create your own sever and host it when you make a lobby. Then type in the commands you want. Infinite ammo, God mode, I don't recall the commands but a Google search should
shagle voojio get what you need.