There's really nothing else I can help you with - everything is here. I already told you, I'm not giving any implementation specific code, so don't expect me to take a look at LOTF (or w/e you use) and tell you how to fix it. Why are you running a server if you don't understand the very basics of how it works in the first place?
Simply put - you need to understand about encryption. What it does, why it's there, and where it is. Whatever server you're already using has it's own cryptography, because it existed before patch 5018, this just needs replacing with the new method, that's all. (although, the login server should remain unchanged). Read up on cryptography - wikipedia is the place to start.
Before you read up on encryption, you might wanna read up on networking, TCP, binary data, streaming, serialization/marshalling etc. They're the basic components that make up your server, if you don't understand them, you won't understand my code.
Basically, you replace the cryptography module, implement a check within your server to decide whether the packets you're sending to/receiving from are the first ones (the key packets already described), if not, enter your normal check for the packet type. You need to modify your packet splitting and sending code to compensate for the TQServer, TQClient padding too. I can't help you with that - because you don't appear to even know how your own server does it - but I can tell you this - if you're using code from this forum, you're doing it badly.