My man, just use any injector, or copy and paste one from ******. I'm sure most private servers do not use a real good anti-cheat. An injector you can use is Extreme Injector I guess, though you will have to set an exception for it on Windows anti-virus. I use it when I cheat on MapleRoyals.
For dll's, why not just learn how to use Cheat Engine and find some of the simple cheats (since vaccing is usually bannable)? Other than that, I cannot help you with that.