If you could understand this you would be busy with your own client making big bucks, why bother helping another guy who could become your competition?
Why use already written source code that works? Oh yea, you can't use GPL code in a commercial client. Wait! Maybe you can sneak it in so you can make money now! How do you think all the other money making spyware clients got their start?

Soapbox off.

Go look at Gnucleus source code or a linux client to see what is little endian etc it is easier. No where does it tell what a GUID is byte order wise, you have to see what others have done, sorry.
Plus you should be working on features and not wasting your time re-hashing old protocol code that has already been written.
Build on top of what has already been done and then post what you have done so other can build on top of that.