Alright. It's pretty straight forward.
1. Download v.55 of MapleStory (can be found on the CaliberMS website in the download section)
2. Install v.55 and whatever.
3. Download the CaliberMS client off the website (also in the download section)
4. Extract the client from the RAR file into your v.55 folder
5. Download DXWnd if you want your MS to be windowed. You can figure that one out for yourself, because it is unnecessary for connecting to the server
6. Open the CaliberMS client in your v.55 folder.
Everything should connect