Mythic began encrypting packets a few years ago, so I don't know if it's still possible to read them.
It might be more practical to read the packets from inside the client's address space after the client decrypts them.
In addition to a C compiler, you'd need a reverse-engineering debugger like OllyDbg and lots and lots of patience.

But it would be a fun project, and you'd learn a lot about programming.
If you decide to play around with this, be warned that Mythic has shut down accounts permanently simply for running the client while it's attached to the debugger. Before you run game.dll you'd need to remove or hook the calls that check for an attached debugger.